【Objective】Based on the current “dual carbon” strategic goal, this study aimed to clarify the current characteristics, spatio-temporal pattern and influencing factors of agricultural net carbon sink, so as to provide the important support for accelerating agricultural sink increase and emission reduction.【Method】Based on the scientific reconstruction of the index system, the carbon sink/carbon emission factor method was used to measure and analyze the current situation of China’s agricultural net carbon sink. Then the spatial autocorrelation model was used to discuss the spatial dependence and spatial heterogeneity. Finally, the least-squares method was used to analyze the main factors affecting the change of its intensity. 【Result】From 2005 to 2022, the total amount of agricultural net carbon sink in China was in an obvious upward trend, although there were some interannual fluctuations, and its evolutionary characteristics could be roughly divided into four stages, namely, “continuous rise”, “fluctuating decline”, “rapid rise”, and “slow rise”; the intensity of agricultural net carbon sink was also in an obvious upward trend, with only a slight difference in the trajectory of the evolution, and the difference in its growth rate could be roughly categorized into four stages: “continuous rapid growth”, “slow growth”, “fluctuating ups and downs”, and “slow growth”. 2022, the amount of agricultural net carbon sink had a large interprovincial difference, with Inner Mongolia being the first and Shanghai being the last, and compared with the year of 2005, all the provinces had a significant increase. In 2022, the net carbon sink intensity of agriculture would be the highest in Henan and the lowest in Qinghai, with all provinces showing different degrees of increase compared with 2005. China’s provincial agricultural net carbon sink intensity as a whole showed obvious spatial dependence, but there was also a local spatial clustering phenomenon, more than 70% of the provinces showed obvious spatial clustering characteristics, and the number of provinces located in the high-high clustering and the low-low clustering was approaching. The structure of arable land use, urbanization level, rural residents' income level and the internal industrial structure of agriculture all had a significant impact on the intensity of agricultural net carbon sink; specifically, the higher the ratio of sown area of grain crops, or the higher the urbanization rate, or the higher the income level of rural residents, or the larger the ratio of plantation industry to animal husbandry, the higher the intensity of net carbon sink in agriculture.【Conclusion】The total amount and intensity of China’s agricultural net carbon sink were in a fluctuating upward trend and there were obvious inter-provincial differences. The intensity of China’s agricultural net carbon sink showed obvious spatial dependence and spatial heterogeneity. The intensity of the agricultural net carbon sink was affected by the structure of arable land use, the level of urbanization, the level of rural residents' income, and the structure of the internal industries of agriculture. The measures should be taken to promote the enhancement of sink and emission reductions and to promote the enhancement of agricultural net carbon sink in agriculture, such as establishing a sound policy support system for the development of low-carbon agriculture, strengthening inter-provincial exchanges and cooperation, and increasing financial support for agriculture.

【Objective】Reasonably increasing planting density combined with appropriate nitrogen (N) application rate is an important technical approach for increasing maize yield and resource use efficiency. Understanding the interactive effects of planting density and N rate on maize growth, evapotranspiration (ET) and water use efficiency (WUE) during the growing season, could provide a basis for improving its use efficiency when increasing planting density and controlling N input in maize production. 【Method】Field experiments were conducted during 2022 to 2023 in Jilin Province. Two maize cultivars, Liangyu 99 (LY99) and Demeiya 3 (DMY3), were used in this study. Three planting densities of 50 000, 70 000 and 90 000 plants/hm² and four N application rates of 0, 100, 200 and 300 kg N·hm^-2 were designed to investigate the effects of planting density and N application rate on grain yield and water productivity of different maize cultivars, as well as the dry matter (DM), soil water content, ET and WUE at various growth stages. 【Result】Planting density significantly affected DM and grain yield of maize, but the response trends varied between cultivars. Grain yields of LY99 with 70 000 plants/hm² was 11.1% and 18.3% higher than that with 50 000 and 90 000 plants/hm², respectively. The average yield of DMY3 planted with 70 000 plants/hm² and 90 000 plants/hm² was 10.5% and 9.3% higher than that of 50 000 plants/hm², respectively. Nitrogen fertilization significantly increased DM and grain yield of maize, and also showed significant interactive effects with cultivar or planting density. Compared with N0, grain yields of LY99 were increased by 38.0% to 60.7% under N1, and the yield increases for DMY3 were 24.4% to 38.2%. Notably, the yield responses to N rates were more pronounced for LY99 compared with DMY3. For both cultivars, the yield differences between low N rate and high N rate enlarged with increasing planting density, with LY99 showing a more distinct performance. The water consumption and utilization of maize plants were also significantly affected by planting density, N rate and their interaction. During the growing season, the total ET of DMY3 continually increased with increasing density, while that of LY99 showed the highest values with 70 000 plants/hm² among different densities. In each density condition, the ET of both cultivars increased with increasing N application rates. The WUE of maize plants showed complex responses to planting density and N rate at different growth stages, due to the varied annual precipitation and distribution patterns. The average increase of water productivity of LY99 under planting 50 000 and 70 000 plants/hm² was 8.6% and 10.4% compared with 90 000 plants/hm² respectively_. DMY3 had the highest water productivity when planting 70 000 plants/hm², which increased by 5.8% and 5.3% compared with 50 000 and 90 000 plants/hm², respectively. The water productivity showed different responses to N rate among the three densities. In general, the difference of nitrogen application under low density was small, but it increased significantly under medium and high density. Compared wtih DMY3, LY99 showed higher increases for water productivity when N fertilizer was applied under medium and high density conditions. The correlation analysis showed that interactive effects of planting density and N rate significantly affected maize yield and water productivity by influencing the water utilization at various growth stages. 【Conclusion】Planting density and N rate had significant interactive effects on maize yield and water utilization in the rain-fed region of Northeast China. The two maize cultivars used in this study could obtain high grain yield and water productivity under a moderately higher density of 70 000 plants/hm² combined with 200 kg N·hm^-2 rate.

Seed shattering is a major factor limiting rice production, and breeding new rice varieties with moderate seed shattering is a key challenge faced by rice breeders worldwide. Rice is the most important cereal crop in China, plays a vital role for national food security. Seed shattering is one of the most important traits during rice domestication, and the abscission zone is the important region to control seed shattering. Compared with wild rice, cultivar has eliminated the seed shattering with partially developed abscission layer. Seed shattering not only has a direct impact on the yield, but also affects the way of its mechanical harvest. In order to breed rice varieties with moderate seed shattering in agricultural production, it is necessary to mine and utilize important seed shattering genes and introduce them into excellent rice varieties for genetic improvement, so as to breed new rice varieties suitable for mechanical harvesting with moderate seed shattering. Several seed shattering genes had been identified by map-based cloning, such as SH4/SHA1, qSH1, OsSh1/ObSH3, and their functional mechanisms had been analyzed. At the same time, new rice materials with moderate seed shattering have been successfully developed through CRISPR/Cas9 gene editing technology, gamma ray mutagenesis technology and gene introduction methods. Seed shattering has an important effect on grain yield and rice harvesting methods, in this paper, we reviewed the methods, physiologic basis, the identification of seed shattering genes and genetic mechanism of seed shattering in rice. At the same time, it is proposed that by using the important genes in excellent rice germplasm resources, could provide reference for exploring the mechanism of rice seed shattering, and breed new rice varieties suitable for mechanical harvesting with moderate seed shattering.

【Objective】Genetic improvement for efficient utilization of maize nutrients represents a crucial method to ensure national food security. Exploring quantitative trait locus (QTL) and related candidate genes of nitrogen use efficiency can provide a theoretical basis for improving the efficiency of nitrogen fertilizer in maize and cultivating high-yield and high-efficiency maize varieties. 【Method】In this study, QTL mapping analysis in one recombinant inbred line (RIL) population constructed by KA105 and KB024 was performed for grain yield under two different nitrogen treatments, including the derived traits partial factor productivity from applied nitrogen (PFPN), low nitrogen tolerance coefficient (LNTC) and nitrogen agronomic efficiency (NAE). Concurrently, integrating the seedling transcriptome data of the parent KA105 under nitrogen treatment, differentially expressed genes were identified, and candidate genes associated with maize nitrogen use efficiency were mined through co-expression analysis. Subsequently, the selected candidate genes were validated using qRT-PCR. 【Result】Through mapping analysis, a total of 36 QTLs distributed across different chromosomes were detected, explaining 1.63% to 17.26% of the phenotypic variation. Among these, eight major QTLs with a phenotypic variation explanation rate exceeding 10% were identified, along with seven genetically stable QTLs commonly identified across different traits or environments. Notably, qNNGYP1 located on chromosome 1 has been repeatedly detected in previous studies, with a phenotypic explanation rate of up to 11.73%. Additionally, other QTLs (qNNGYP1, qPFPN1) co-located in this interval across different environments, suggesting it as a focal region for further investigation. Combining transcriptome data of seedlings under low nitrogen stress, 39 differentially expressed genes within these QTL intervals were identified, and 6 key genes were identified through co-expression network prediction. The result of qRT-PCR indicated that the expression trends of the candidate genes under both nitrogen treatments were consistent with the transcriptome data. Specifically, GRMZM2G366873 was involved in the regulation of auxin homeostasis and may participate in maize responses to low nitrogen stress, drought stress, and boron stress through auxin signal transduction, also regulating ear length. GRMZM2G414192 was involved in the response of the photosynthetic system to low nitrogen stress and was regulated by brassinosteroids. GRMZM2G414043 was associated with maize grain length and biomass, while GRMZM2G040642 may be involved in the long-distance signal transduction of nitrogen. 【Conclusion】In summary, a total of 36 QTLs were identified, distributed across chromosomes 1, 4, 5, 7, 8, and 9, including eight major QTLs (PVE>10%). The candidate genes GRMZM2G366873, GRMZM2G414192, GRMZM2G414043, and GRMZM2G040642 were identified as potential genes for maize nitrogen efficiency.

【Objective】Analyzing the yield and yield related traits of Sichuan wheat varieties from 2000 to 2020, providing reference for genetic improvement of yield in Sichuan wheat varieties. 【Method】From 2019 to 2022, a community trial design was used to measure the yield and related traits of 145 wheat varieties in Sichuan Province since 2001 to 2016, as well as 60 high-yield wheat varieties (Varieties with top yields in regional trials in Sichuan Province over the years) since 2000 to 2020. This data was used to analyze the trend of yield and yield related trait changes in Sichuan wheat cultivars cultivated from 2000 to 2020. 【Result】145 Sichuan wheat varieties from 2001 to 2016 have an average annual genetic gain of 37.20 kg·hm^-2 or 0.66% in yield. Grain number per spike and effective spike number per unit area showed an increasing trend, while thousand grain weight and plant height showed a decreasing trend. Correlation analysis showed that effective spike number per unit area was positively correlated with yield. Path analysis showed that the continuous increase of effective spike number per unit area (annual increase 0.42×10⁴/hm² or 0.13%) was the main factor for the increase of yield potential of high-yielding varieties. The average annual yield genetic gain of 60 high-yield wheat varieties from 2000 to 2020 was 61.10 kg·hm^-2 or 0.89%, the effective spike number per unit area showed an increasing trend, the plant height showed a decreasing trend, and the grain number per spike and thousand grain weight had almost no change. Correlation analysis shows that there was a significant positive correlation between yield and the number of effective ears per unit area. Path analysis showed that the continuous increase in effective spike number per unit area (with an average annual increase of 1.80×10⁴/hm² or 0.51%) was also a major factor in improving the yield potential of 60 high-yield wheat varieties in Sichuan from 2000 to 2020. 【Conclusion】The improvement and breeding of wheat yield heritage in Sichuan Province has made some progress, especially the improvement effect of high yield breeding is remarkable, and the yield level of wheat varieties in Sichuan Province is gradually increasing. The continuous increase in effective ears per unit area was the main factor for improving the yield potential of Sichuan wheat varieties. High grain number per spike and thousand grain weight are important foundations for high yield in Sichuan wheat, but their genetic improvement is in a bottleneck period. Increasing the effective spike number per unit area is the key to furtherly improve the yield of wheat in Sichuan.

【Objective】Exploring the genetic loci and related genes that control cottonseed size traits to lay a foundation for subsequent study on the molecular mechanism cottonseed size formation. 【Method】The upland cotton recombinant inbred line (RIL) population composed of 300 lines was used as the research material. Seven phenotypic traits including cottonseed index (SI), seed length-cutting acreage (SLA), seed length-cutting perimeter (SLP), seed length (SL), seed width (SW), length-width ratio (LWR) and seed roundness (SR) were evaluated in four environments. The RIL population was genotyped by liquid phase chip strategy. The high-quality single nucleotide polymorphism (SNP) markers and phenotypic data were subjected to perform genome-wide association study (GWAS), and quantitative trait nucleotides (QTNs) associated with cottonseed size-related traits were mined. The genetic effects of QTNs were analyzed to identify candidate genes. 【Result】Seven cottonseed size-related traits showed a continuous normal distribution in four environments, which expressed a sizable phenotypic variation. The coefficient of variation ranged from 1.82% to 10.70%. The influencing effect on trait formation were basically as genotype>environment>genotype × environment, indicating suitability for GWAS analysis of these results. Correlation analysis showed that the seed index was significantly correlated with SLA, SLP, SL and SW, and LWR was significantly correlated with SR, indicating the possible existence of pleiotropic loci. GWAS was performed using the 3VmrMLM model, and a total of 47 QTNs were associated with these seven traits. A total of 11 QTNs were associated on chromosome A07, of which three physical loci in the region of 71.99-72.87 Mb, A07:71993462, A07:72067994 and A07:72198802 were very close and simultaneously associated with SI, SLA, SLP, SL and SW in four environments. The average value of R2 between markers was>0.8 (P<0.001), showing a large linkage disequilibrium. Genetic effect analysis showed that there were two haplotypes in this region. Among these cottonseed size relating traits, haplotype Ⅱ and haplotype I were significantly different, indicating that these loci directly affected cottonseed size traits and could be used for molecular marker-assisted selection. The expression patterns of the genes in the interval were analyzed using TM-1 transcriptome data. The results revealed that Gh_A07G1767 was preferentially expressed and Gh_A07G1766 specifically expressed at the stage of cottonseed development. These results speculated that these genes may play an important role in the growth and development of cottonseed.【Conclusion】47 QTNs were identified, and two candidate genes related to cottonseed development were screened.

With the continuous improvement in rice cultivation techniques, China has maintained a high rice production level of about 210 million tons over the past decade. Direct-seeding rice cultivation technology, recognized for its efficiency and simplicity, has been favored by Chinese farmers. However, controversies persist regarding direct-seeding rice compared to transplanted rice in national-scale production. Thus, this study employed meta-analysis techniques to quantify disparities in grain yield, economic benefit, rice quality, lodging characteristic, and greenhouse gas emissions between direct-seeding rice and transplanted rice. Our results indicated that direct-seeding rice significantly reduced grain yield by an average of 6.3% relative to transplanted rice, which was main due to the reduced total spikelet (-3.8%) and filled-grain percentage (-1.8%). In different planting systems in China, the yield of direct-seeding rice had significantly decreased compared to transplanted rice, and the direct-seeding rice-induced reductions in yield of single rice (-10.9%) and late rice (-13.1%) were higher than those of middle rice (-4.8%) and early rice (-4.4%). The grain yield reductions for direct-seeding rice were from 10% to 20% in Jilin, Liaoning, Xinjiang, Ningxia, Shandong, Jiangsu, and Zhejiang provinces, meanwhile Heilongjiang and Jiangxi provinces saw reductions of 5% to 10%, but it had no significant effect in other provinces. Direct-seeding rice resulted in comparable net economic return relative to transplanted rice (p> 0.05). Direct-seeding rice reduced milled rice rate (-3.1%) and gel consistency (-3.5%), improved appearance quality (chalkiness percentage and chalkiness degree, which decreased by 25.3% and 22.5%, respectively), whereas no significant effects were observed on nutrition quality and taste value. Direct-seeding rice increased lodging index at base of the first (+12.4%) and third (+10.3%) internodes, but not at the second internode, indicating an increase in risk of lodging relative to transplanted rice. In terms of greenhouse gas emissions, direct-seeding rice fields showed reductions in methane emissions (-42.8%), global warming potential (-36.2%), and greenhouse gas intensity (-41.1%) compared to transplanted rice fields, while promoting nitrous oxide emissions (+29.1%). In addition, a review was recounted on nitrogen utilization and its loss, water and energy use efficiency, and weed incidence. Finally, the recommendations for the future advancement of direct-seeding rice were proposed, main focusing on rice variety breeding, rice cultivation technique optimization, rice planting area layout, as well as policies and services with the goal of technological innovation and regionalized application of direct-seeding rice cultivation technology in China.

【Objective】FWL (Fruit Weight2.2-Like) gene is a negative regulator of cell proliferation, which not only regulates plant organogenesis and organ size, but also participates in the regulation of metal ion transport accumulation and signal transduction. Analyzing of the function of OsFWL3 gene is helpful to reveal the transport mechanism of trace metal elements in crops. It provides theoretical support for reducing heavy metal accumulation and improving crop quality. 【Method】The gene information, genome structure and phylogenetic tree of OsFWLs family were analyzed by bioinformatics method, and the expression profile of OsFWL3 gene was predicted. Two OsFWL3 knockout lines were obtained using CRISPR/Cas9 gene editing technology. Then wild type and Osfwl3 mutants were treated with ZnSO₄ at seedling stage and filling stage, respectively. The phenotypes of plants and grains after treatment were analyzed, and the content variation of metal elements such as Zn was determined to explore the effects of OsFWL3 on the transport and accumulation of metal ions and seed quality. 【Result】The gene function of OsFWLs family is similar to some extent. OsFWL3 gene is highly expressed in anther and panicle, indicating that it is closely related to reproductive development of rice. The number of primary branches, grian length, grain thickness and 100-grain weight of Osfwl3 mutants are significantly larger than WT. OsFWL3 affects the content and distribution of Zn and other metal ions in rice seedlings and grains. The deletion of OsFWL3 gene affects the competitive transport of Zn, Cd and Mn from underground to above-ground, lower grain to central grain and husk to brown rice. 【Conclusion】OsFWL3 gene affects the distribution of Zn and other metal ions in rice grains and plants, and it plays an important role in regulating the growth and development of rice plants and grain size.

【Objective】 Maize stalk rot is one of the common and most devastating diseases in major maize production areas in China. Under natural conditions, maize stalk rot is mostly caused by the synergistic infection of various pathogens. The purpose of this study was to screen elite maize germplasms resistant to the synergistic infection with F. graminearum and F. verticillioides. Meanwhile, QTN associated with resistance to the infection by synergistic infection of two Fusarium species and the candidate resistance genes were identified, which will provide gene resources and theoretical reference for molecular breeding of maize variety resistant to synergistic infection of different pathogens.【Method】 Using a maize natural population as experimental materials, the maize stalk rot phenotypes were investigated upon simultaneous infection with F. graminearum and F. verticillioides. Furthermore, GWAS analysis was conducted to identify significant resistance SNP and to predict candidate genes for stalk rot resistance.【Result】 Through the phenotypic analysis of stalk rot caused by synergistic infection under both field and laboratory conditions, it was found that inbred lines from different sources and subgroups showed significant phenotypic variation. More specifically, the field assay results showed that the inbred lines collected from China were more resistant and that from USA were more susceptible to synergistic infection. Moreover, the inbred lines of tropical and subtropical subgroup were more resistant, whereas the inbred lines of Mixed subgroup more susceptible. The seedling assay results under laboratory condition showed that the lines collected from USA were more resistant, whereas that from CIMMYT were more susceptible. The lines of SS subgroup were more resistant, and that of Mixed subgroup were more susceptible. By integrating field and laboratory phenotypic data, 29 and 16 lines with higher levels of resistance to synergistic infection were screened out respectively, and 6 resistant lines were identified under both conditions. Moreover, based on the field phenotype GWAS, 18 QTNs associated with the resistance were identified, and 93 candidate genes associated with stalk rot resistance to synergistic infection were mined. Among these candidate genes, four genes showed haplotype variation, whose expression levels were up-regulated in disease-resistant lines.【Conclusion】 Using the natural population of maize with great diversity in genetic background, 6 resistant lines to the synergistic infection with Fusarium spp. were identified under two conditions, which can be used as potential germplasm resources for maize stalk rot resistance in the future. Four candidate genes that might be involved in the resistance to synergistic infection were identified by GWAS, which will provide genetic resources for the breeding maize varieties with enhanced resistance to stalk rot caused by F. graminearum and F. verticillioides.

【Objective】Taikemai33, derived from a cross between Zhengmai366 and Huaiyin9908, is a new released wheat cultivar with high quality, high yield, and excellent disease resistance, which has a broad genetic base, and a high potential for application in wheat production. The objective of this study is to dissect the genetic composition of Taikemai33 to provide information for parental selection to use this cultivar to develop more new wheat cultivars. 【Method】Taikemai33 and its pedigree parents including Zhengmai366, Huaiyin9908, Yumai47, PH82-2-2, Yumai13, Yumai 2 hao, Bainong3217, Yanda24, Xiannong39, Fengchan 3 hao and Funo were screened using the 55K wheat SNP chip to dissect the genomic composition of Taikemai33 to evaluate the genetic contributions of each parental line to Taikemai33. 【Result】The similarity coefficient between Taikemai33 and its pedigree parents ranged from 0.72 to 0.93, and the genetic composition of Taikemai33 was highly similar to Zhengmai366, the pedigree mother parent, with a genetic similarity coefficient of 0.93. SNP marker analysis showed that the pedigree parents contributed different proportion to the genome of Taikemai33, with the pedigree mother contributed 66.57%, whereas the pedigree father contributed 33.43%, indicating that Taikemai 33 inherits more genetic materials from the maternal lineage. Furthermore, the pedigree mother contributed 71.0%, 85.0% and 49.4% to subgenome A, B and D of Taikeimai33, whereas those were 29.0%, 15.0% and 50.6% contributed by the pedigree father. For each chromosome, the pedigree mother contributed more on chromosome 1A, 2A, 3A, 4A, 7A, 1B to 7B, 1D and 2D, whereas the pedigree father contributed more on chromosome 5A, 4D, 6D and 7D. The contributions of the pedigree parents on 6A, 3D and 5D were equal. Taikemai33 genotype map showed that the contribution loci of the pedigree mother were distributed in clusters on chromosome 1A, 5A, 7A, 2B, 7B, 2D, with those from the pedigree father were on chromosome 4A, 5A, 6D, 7D. Interestingly, among the polymorphic SNP loci, between Zhenmai366 and Huaiyin9908, Taikemai33 showed 109 loci that were absent in both parents, distributing on 19 chromosomes except 1A and 6A. Chromosome 4A, 2B, 6B and 7D of Taikemai33 confer most of the polymorphic SNPs in clusters with cluster number of 10, 9, 11, and 9. 【Conclusion】We constructed the genotype map and dissected the genetic composition of Taikemai33, determined the loci contributed by the pedigree parents and identified that Taikemai33 inherited more genetic materials from the pedigree mother and conferring some specific loci different with the pedigree parents.

【Objective】 Starch is the main component of wheat kernel and plays an important role in processing. The gelatinization characteristic of starch is an important index to evaluate its quality. The genetic variation of starch gelatinization was studied to provide basis for improving wheat quality. 【Method】 Seven starch gelatinization traits, including gelatinization temperature, peak time, peak viscosity, trough viscosity, final viscosity, decay value and recovery value, were phenotypically determined in 205 winter wheat varieties. Genome-wide association analysis was performed using 90K chip, and haplotype analysis was performed on the stable and significant sites found. 【Result】 The seven characteristics, such as pasting temperature, showed abundant variation in different environments, and the coefficient of variation of attenuation value was the largest (29.31%-31.14%). There were significant differences among genotype, environment and genotype × environment, and the generalized heritability was 0.69-0.86. Through genome-wide association analysis, we found 198 loci that showed significant associations with seven traits. It was distributed in 20 other linked groups except 6D chromosome. There were 58 sites that were stable in 2 or more environments, involving all 7 traits, such as pasting temperature (10), peak time (5), peak viscosity (12), trough viscosity (10), final viscosity (7), break down (4) and set back (10), which could explain 5.54%-22.21% of genetic variation, twenty-one new sites were identified. By haplotype analysis of multiple effector sites that exist in multiple environments and have high phenotypic contribution, Four haplotypes, Hap1 (66.84%), Hap2 (16.84%), Hap3 (9.70%) and Hap4 (6.63%), were found at Kukri_c17417_407 on chromosome 4A, which were significantly related to peak viscosity and break down. Where Hap2 is the peak viscosity and high break down. (P<0.0001). The distribution frequency of varieties (lines) containing haplotype Hap2 in different ecological regions was from high to low as Huanghuai winter wheat region>foreign varieties>Southwest winter wheat region>Middle and lower reaches of Yangtze River winter wheat region>Northern winter wheat region. There were 11 single cause multieffect sites, among which there were 3 multiple effect sites associated with final viscosity, set back, peak time and trough viscosity. Jagger_c4026_328 and other 11 stable genetic loci located on 1B, 2A, 3A, 3B, 4A, 4B, 5B and 6B were mined, and 11 candidate genes that might be related to wheat starch gelatinization traits were screened. 【Conclusion】 In this study, RVA parameters had high heritability, and the RVA parameters of wheat starch were different in different environments. In this study, RVA parameters had high heritability, and the RVA parameters of wheat starch were different in different environments. 58 stable loci were detected that were significantly associated with starch gelatinization traits, and 4 different haplotypes were identified on chromosome 4A that were significantly associated with peak viscosity and break down, and 11 candidate genes related to starch gelatinization were screened, which could provide help for marker-assisted high-quality wheat breeding.

【Objective】 Improving the nitrogen transport and accumulation of nutrient organs after wheat flowering, as well as improving the nitrogen accumulation characteristics of wheat grains, is beneficial for increasing the nitrogen accumulation and yield of wheat. This study aimed to clarify the physiological mechanisms underlying the differences in nitrogen utilization efficiency among wheat plants at different yield levels, so as to provide a theoretical basis for reducing yield differences and improving nitrogen utilization efficiency and to achieve high yield and efficient production of wheat.【Method】 The field experiments were conducted in Shiwang Village, Xiaomeng Town, Shandong Province for two consecutive years from 2020 to 2022. Using Tobacco Farmer 1212 as the planting material, three yield levels of wheat fields with a perennial winter wheat yield of around 10 500 kg·hm^-2 (S), 9 000 kg·hm^-2 (H), and 7 500 kg·hm^-2 (M) were selected to compare and analyze the differences in plant nitrogen accumulation and transport, grain nitrogen accumulation characteristics, and grain yield in wheat fields with different yield levels.【Result】 Compared with H and M wheat fields, S wheat field significantly increased the number of spikes per unit area and thousand grain weight, with grain yield 19.64%-27.91% and 51.68%-80.87% higher than H and M wheat fields, respectively, resulting in the highest nitrogen absorption efficiency, nitrogen partial productivity and nitrogen harvest index. The nitrogen accumulation in the nutrient organs of S wheat field during the flowering period increased by 14.22-42.11 kg·hm^-2 and 53.74-103.16 kg·hm^-2, respectively. The nitrogen accumulation in mature nutrient organs was S, H>M. Compared with H and M wheat fields, S wheat field significantly increased the nitrogen transport of pre flowering nutrient organs and nitrogen accumulation after flowering, and increased the contribution rate of nitrogen accumulation in post flowering nutrient organs to grains, thereby achieving the highest nitrogen accumulation in mature grains. The S wheat field significantly increased the content of free amino acids and soluble proteins in flag leaves after flowering, for promoting the inter source sink transport of nitrogen. According to the logistic equation fitting, the S wheat field significantly increased the maximum and average accumulation rates of grain nitrogen, prolonged the duration of grain nitrogen accumulation, and was the main reason for obtaining the highest grain nitrogen accumulation.【Conclusion】 Suitable soil environment in S wheat field could promote the transfer of stored nitrogen from vegetative organs to grain, and increase the rate of grain nitrogen accumulation and prolong the duration of grain nitrogen accumulation, which was the main reason for the highest grain yield and nitrogen use efficiency.

【Objective】 The rice-crab co-culture is a predominant three-dimensional ecological cultivation model in northern Chinese rice fields. The water-soil interface is a key area for material cycling within this system. In this paper, studying the diversity and structure of microbial communities at this interface aimed to understand its evolution and support research on the ecological health of water and soil in rice-crab co-culture systems. 【Method】 Eight long-term rice monoculture systems and eight long-term rice-crab co-culture systems (>20 years) were selected in a typical rice-crab co-cultivation area in Panjin, Liaoning province. Based on measurements of physicochemical indicators of rice field water and soil, as well as high-throughput sequencing technology of the 16S rRNA gene, the study compared the effects of two rice cultivation systems on the properties and bacterial community structures of the water-soil interface in paddy fields. 【Result】 (1) The introduction of crabs significantly reduced the unique microbial communities at the water-soil interface. Specifically, the number of unique operational taxonomic units (OTUs) in surface water and interfacial soil decreased by 27.0% and 71.2%, respectively. However, the introduction of crabs had no significant effect on alpha diversity in surface water, but it reduced the richness of bacterial communities in interfacial soil. (2) The introduction of crabs significantly altered the structure and composition of the water-soil interface bacterial community. The introduction of crabs significantly increased the relative abundance of Proteobacteria (30.4%) and decreased the relative abundance of Acidobacteria (39.9%) in surface water. Simultaneously, it increased the relative abundance of Planctomycetes (21.1%) and decreased the relative abundance of Ignavibacteriae (15.1%) and Nitrospirae (21.7%) in interfacial soil. (3) Proteobacteria and Bacteroidetes were not only core species at the water-soil interface of rice field systems, but also key species in co-occurrence networks, playing important roles in stabilizing ecological networks. (4) The introduction of crabs into rice fields increased the complexity and stability of the bacterial co-occurrence network in the interface soil, but decreased it in the paddy field water. (5) Linear regression analysis showed that NO₃^-- N concentration in surface water and interface soil pH were the main driving factors influencing the diversity and stability of their respective bacterial community structures. 【Conclusion】 The introduction of crabs significantly altered the microbial community structure and diversity at the water-soil interface in rice fields. The increase in nutrient salts in the water posed a risk of reducing the stability of the aquatic microbial community. However, the rice-crab co-culture shaped a more stable bacterial community in the interface soil, which facilitated nutrient cycling and enhanced crop nutrient utilization efficiency.

【Objective】Based on the field staging experiments, this study revealed the different responses of winter wheat and summer maize sowing date adjustments in growth and development, photosynthetic physiological characteristics, grain filling, yield formation and quality to climate warming in northern area of North China, providing scientific basis for agricultural production measures to cope with climate change in North China Plain.【Method】Different sowing date experiments of winter wheat and summer maize have been conducted at Hebei Gucheng Agricultural Meteorology National Observation and Research Station in northern area of North China from 2017 to 2023, which were set up in four sowing dates, including 10 d early sowing, 10 d late sowing, 20 d late sowing, and control. The growth process, above-ground dry matter accumulation and distribution, photosynthetic characteristics of leaves, grain filling rate, yield agronomic traits, and grain nutrients of winter wheat and summer maize were observed. 【Result】 The whole growth period of winter wheat was shortened with the delay of sowing date, mainly because of the shortening of seedling stage before winter. There was a parabolic relationship between the whole growth period and sowing date of summer maize. The seedling stage was shortened by 1.3 d, and the flowering stage and grain formation-filling stage were extended by 1.5 d and 1.6 d for every 10 d delay of sowing date. The grain filling characteristics of winter wheat and summer maize were not sensitive to sowing date adjustments, and the grain filling rate of summer maize was little different during different sowing dates, but the grain formation period, the filling end date and the peak date were successively delayed due to the delay of sowing date, and the duration of filling days was shortened by 4.0 d for every 10 d delay of sowing date. Under the background of warm autumn and winter in northern wheat region, the sowing duration of winter wheat was extended, while its influence on the yield was obviously weakened. The delay of sowing date with the increase of sowing seed amount would result in yield increase slightly. The yield of summer maize decreased significantly with the delay of sowing date, and the decline rate of theoretical yield was 1 381.50 kg·hm^-2 for every 10 d delay of sowing date, but the yield of winter wheat and summer maize showed a jumping decease for 20 d late sowing. The grain distribution rate increased by 1.67% for winter wheat, decreased by 1.57% for summer maize with every 10 d delay of sowing date. As a result, the harvest index increased by 0.017 for winter wheat, and decreased by 0.016 for summer maize with every 10 d delay of sowing date. The leaf photosynthetic rates (Pn) of winter wheat and summer maize were also different in response to sowing date, they were similar for winter wheat during different sowing dates, while decreased by 1.21 μmol·m^-2·s^-1 for summer maize for every 10 d delay after sowing date. Sowing date adjustments had no significant effects on grain quality of winter wheat and summer maize in northern area of North China. 【Conclusion】Extending suitable sowing date range and sowing date delay of winter wheat in North China Plain were positive and effective measures to adapt to climate warming. The early sowing of summer maize in North China Plain might avoid the negative effects of high temperature and heat damage, and would promote the increase of yield.

【Objective】To develop high-yielding and FHB-resistant wheat cultivars in the Yellow and Huai River Valley Winter Wheat Zone (YHWZ), simultaneously improving of yield and resistance was conducted in this study.【Method】Using the elite parent dwarf male sterile (DMS) wheat combined with double haploid (DH) technology and molecular marker assisted selection (MAS) of Fhb1 (DMS wheat molecular breeding strategy), DH lines were developed using Sumai 3 as a donor (FHB- resistant parent) and Zhoumai 16’s DMS wheat, Zhoumai 16, Lunxuan 136 and Lunxuan 6 as recipient parents. The agronomic traits (plant height, heading date, yield, etc.) and FHB resistance were evaluated for these DH lines.【Result】A total of 51 Fhb1-DH lines characterized by facultative growth habit, semi-dwarf and white grains were selected using this strategy. The average number of infected spikelets of 51 lines were 5.7 and 7.3 at the 2020Henan and 2020Beijing sites, respectively, and average disease severities were 27.7% and 35.2%, which is not different from moderately susceptible control Huaimai 20. There was no significant difference in grain yield per hm² between the mean performance of the 51 lines and the control Zhoumai 18. DH116 (Lunxuan 20), a promising line from the 51 lines, was further evaluated for FHB resistance and agronomic traits in multiple environments. The resistance of Lunxuan 20 to FHB was significantly improved, and no significant difference was found in the number of infected spikelets or disease severity between Lunxuan 20 and moderately or highly resistant controls at four sites. Lunxuan 20 showed slightly greater grain yield per hm², and significantly higher number of spikelets per spike and thousand grain weight (P<0.05), earlier heading date and shorter plant height (P<0.05) than the control Zhoumai 18 in two environments. The grain yield per hm² of Lunxuan 20 was 4.6% and 1.7% higher than the control cultivar Bainong 207 in the two list trials of Henan Province, and 3.5% higher than Bainong 207 in the demonstration trial. Resistance of Lunxuan 20 to FHB ranged from moderate susceptibility to moderate resistance in two-year list tests using the single-floret injection and spray inoculation methods. Lunxuan 20 carries the semi-dwarfing gene Rht-D1b at the Rht-D1 locus, and the recessive alleles vrn-A1, vrn-B1 and vrn-D1 associated with the winter growth habit at the Vrn-A1, Vrn-B1 and Vrn-D1 loci. Based on the wheat 660K single nucleotide polymorphisms (SNPs), 64.7% of the SNPs were shared by Lunxuan 20 and its parents, and the direct genetic contributions of Zhoumai 16, Lunxuan 136, Lunxuan 6 and Sumai 3 to Lunxuan 20 were 69.8%, 12.6%, 6.1% and 11.5%, respectively.【Conclusion】A high-yielding and FHB-resistant wheat cultivar Lunxuan 20 was bred using the DMS wheat molecular breeding strategy.

【Objective】 The heading date plays a crucial role in influencing the regional adaptation and yield of rice (Oryza sativa L.). The identification of early heading genes contributes significantly to enhancing and fine-tuning the regulatory network that controls rice heading, which provides valuable genetic resources for molecular breeding with the goal of achieving early maturity and high yield in rice. 【Method】 CL33, a chromosome segment substitution line with early heading, and 93-11, its recipient parent with late heading, were used as research materials to investigate and analyze their major agronomic traits. Two DNA pools were constructed, comprising plants exhibiting extremely early and late heading. Whole-genome resequencing and BSA-Seq analyses were then conducted to locate the genomic region associated with the heading date. In the subsequent steps, InDel markers within this identified region were developed for fine mapping. The gene LOC-Os08g07740 emerged as the primary candidate gene within localization intervals, determined through gene prediction, candidate gene analyses, as well as references to relevant literatures. This candidate gene was subsequently cloned and analyzed for allelic variations. Moreover, we explored the genetic and phylogenetic relationships of the LOC_Os08g07740 gene within the three rice subgroups, Indica, Japonica and O. rufipogon. This analysis involved studying genomic data within approximately 40 kb upstream and downstream of the gene utilizing bioinformatics software.【Result】 Under both natural long-day and short-day conditions in Nanning, Guangxi, CL33 exhibited a 20-25 days shorter than its recipient parent 93-11. Moreover, under natural long-day conditions, the agronomic traits of CL33 were largely similar to those of 93-11, with the exception of a shortened spike length and a reduced number of grains per spike. Genetic analysis revealed that the early heading trait in CL33 was controlled by a recessive gene. This gene was finely localized within a 100 kb region between the markers PSM8-6 and PSM8-8 on the short arm of rice chromosome 8, encompassing 15 predicted candidate genes. Significantly, the candidate gene ORF13 (LOC_Os08g07740), which shared alleles with known heading date genes like DTH8/Ghd8 emerged as a key candidate. Sequencing and sequence alignment of ORF13 demonstrated an 888 bp coding sequence without introns, encoding a protein of 295 amino acids. Compared to the recipient parent 93-11, LOC_Os08g07740 in CL33 featured a 6 bp insertion and a 9 bp deletion between the 535-536th and 820-821st base pairs, respectively, resulting in consequential amino acid sequence alterations. Hence, it was tentatively named OsEHD8 as the target candidate gene. Genetic evolutionary analyses indicated a significant decrease in genetic diversity within the LOC_Os08g07740 gene in Indica and Japonica compared to O. rufipogon, with a 62.53% decrease in Indica and a 53.76% decrease in Japonica. Nevertheless, the differences in genetic diversity between Indica and Japonica were not statistically significant. The LOC_Os08g07740 gene featured a total of 13 haplotypes, with the Hap_2 possibly representing the common ancestor of the three subgroups. Geographical isolation or environmental differences might have led to the fixation of different haplotypes in the Indica and Japonica subgroups. These findings suggested that the LOC_Os08g07740 gene underwent directional selection in the three subgroups.【Conclusion】 OsEHD8, identified as a functional allele of DTH8/Ghd8, played a key role in promoting early heading in rice under both natural long-day and short-day conditions. Moreover, the chromosomal segment substitution line CL33, which carried the OsEHD8 allele, exhibited no significant differences in other agronomic traits compared to the recipient parent 93-11 under natural long-day conditions, except for a shorter spike length and a reduction in grains per spike.

【Objective】This study aimed to explore the differences in genome-wide DNA methylation patterns and their relationships with associated gene expression in different heat-tolerant sesame varieties under high temperature stress, in order to gain a deeper understanding of the regulatory mechanisms of DNA methylation in sesame's response to high temperature stress, and to provide a theoretical basis for heat tolerance breeding in sesame. 【Method】Two sesame varieties, Zhengtaizhi 3 (heat-tolerant) and Shandong White Sesame (heat-sensitive), were selected as experimental materials and cultivated under high temperature (41 ℃) and control (30 ℃) conditions for 10 days. Nanopore sequencing technology was used to conduct methylation sequencing of the genomic DNA of these two sesame varieties, and transcriptome sequencing was performed to analyze changes in the expression of associated genes. Minimap 2 software was utilized for reference genome sequence alignment, and Tombo software was employed to detect 5mC, CpG, and 6mA methylation sites. Differentially methylated regions (DMRs) were identified based on a genome segmentation approach. Finally, functional annotation and pathway analysis of DMR-associated differentially expressed genes (DMR-DEGs) were conducted using GO, COG, and KEGG databases. 【Result】Under high temperature stress, significant changes were observed in the genome-wide DNA methylation patterns of both Zhengtaizhi 3 and Shandong White Sesame. Specifically, the m6A and cytosine methylation (mC) contents of Zhengtaizhi 3 increased, while those of Shandong White Sesame decreased. A total of 621 DMRs (Zhengtaizhi 3) and 374 DMRs (Shandong White Sesame) were identified across the entire genome, mainly distributed in promoter and intergenic regions. Further analysis revealed that these DMRs were significantly associated with 113 DMR-DEGs (Zhengtaizhi 3) and 56 DMR-DEGs (Shandong White Sesame), respectively, and that demethylated DMRs were closely related to upregulated gene expression. Functional annotation results indicated that these DMR-DEGs were primarily involved in biological processes such as carbohydrate transport and metabolism, posttranslational modification, protein turnover, signal transduction, and secondary metabolite biosynthesis. 【Conclusion】This study revealed the differences in genome-wide DNA methylation patterns and their relationships with associated gene expression in different heat-tolerant sesame varieties under high temperature stress. Zhengtaizhi 3, a heat-tolerant sesame variety, regulated the expression of related genes by increasing DNA methylation levels under high temperature stress, while Shandong White Sesame, a heat-sensitive variety, exhibited a decreasing trend in methylation levels. In particular, the dynamic changes in CpG site methylation played a crucial role in regulating sesame's response to high temperature stress. These findings provide new insights and theoretical support for understanding the mechanisms of sesame heat tolerance and for heat tolerance breeding.

【Objective】Pepper mild mottle virus (PMMoV) is one of the major viruses that harm peppers worldwide. The 126 kDa protein is an important pathogenic factor encoded by PMMoV, but its pathogenic mechanism remains unclear. This study aims to screen for pepper host factors that interact with the 126 kDa protein, and to provide a theoretical basis for elucidating the pathogenic mechanism of PMMoV.【Method】Firstly, the bait vector pGBK-126 kDa was constructed using homologous recombination. Using pepper leaves as experimental materials, total RNA was extracted from pepper leaves using the Trizol method, and a pepper yeast cDNA library was prepared. Subsequently, the cDNA library was screened using pGBK-126 kDa, and the screening results were subjected to sequence alignment and bioinformatics functional analysis using NCBI and Uniprot. Based on the alignment and analysis results, host factors that may participate in plant disease resistance pathways were selected, and their full-length CDSs were cloned and constructed into the pGADT7 vector. Yeast two-hybrid (Y2H), BiFC, and LCI were used to further verify the interaction between 126 kDa and host factors. Finally, the role of transiently overexpressed host proteins during PMMoV infection was analyzed.【Result】High-quality pepper RNA was extracted without degradation. A high-quality yeast cDNA library was obtained, and the bait plasmid pGBK-126 kDa was successfully constructed. A total of 18 pepper host factors that interact with the 126 kDa protein were screened. Bioinformatics analysis revealed that these 18 host factors are widely involved in multiple pathways such as plant enzyme systems, regulation of material and energy metabolism, DNA-binding transcription, hormone synthesis, and defense responses. Among them, three host factors (LA2, PDHE1, BXL1) showed interactions with 126 kDa in one-to-one Y2H interaction verification, indicating the reliability of the initial screening results. The interaction between 126 kDa and BXL1 was further verified in vitro and in vivo using BiFC and LCI. Transient overexpression of BXL1 significantly inhibited PMMoV infection.【Conclusion】The pGBK-126 kDa bait plasmid was successfully constructed. Based on this plasmid, 18 interacting host factors were obtained when screening the yeast cDNA library, which are widely involved in multiple pathways of plant life activities. The screening results were verified to be reliable. Among them, BXL1 interacts with 126 kDa both in vitro and in vivo, and can inhibit PMMoV infection. The results can provide a good theoretical and material basis for further exploring of the infection mechanism of PMMoV.

【Objective】Based on the long-term experiment in the North China Plain (NCP), the differences in soil nutrient and aggregate nutrient distribution between diversified crops and wheat-maize rotation systems were investigated. Additionally, it provided a comprehensive evaluation of soil quality indices (SQI), offering a scientific basis for enhancing soil quality and productivity in the NCP. 【Method】Four diversified crop rotation systems were evaluated, including spring sweet potato-winter wheat-summer maize (Psw-WM), spring peanut-winter wheat-summer maize (Pns-WM), spring sorghum-winter wheat-summer maize (Ps-WM), with winter wheat-summer maize (WM-WM) serving as the control. The soil samples from the 0-40 cm depth were collected during the second rotation in 2022, at the flowering and harvesting stages of winter wheat. The soil enzymes activities, aggregate stability, organic matter, and concentrations of nitrogen, phosphorus, and potassium in soil and aggregates of different sizes (>2.00 mm, 0.50-2.00 mm, 0.25-0.50 mm, and <0.25 mm) were assessed. The SQI for each crop rotation system was then comprehensively evaluated. 【Result】Compared with WM-WM, the three other crop rotations increased soil inorganic nitrogen content. Psw-WM significantly enhanced organic matter in the 0-20 cm layer, total nitrogen in soil aggregates (>2.00 mm, 0-10 cm), and organic matter in soil aggregates (>2.00 mm and 0.50-2.00 mm, 0-10 cm), which also increased cellulase, catalase, and alkaline protease activities. Pns-WM improved organic matter in the 20-40 cm layer and available potassium in soil aggregates (0.25-0.50 mm and >2.00 mm, 10-20 cm), as well as organic matter in soil aggregates (0-10 cm, >2.00 mm and 10-20 cm, >0.50 mm), which also increased sucrase, urease, and alkaline protease activities. Psw-WM improved the stability of 0-10 cm soil aggregates, while Pns-WM improved the stability of 0-30 cm soil aggregates. Both Pns-WM and Psw-WM significantly improved the SQI, with Pns-WM showing a higher improvement than Psw-WM. The path analysis revealed that the average weight diameter (MWD) of aggregates was a direct and significant affecting SQI. It also had a significant indirect positive effect on SQI by influencing inorganic nitrogen. Additionally, the increased organic matter led to a higher proportion of large aggregates, which significantly affected SQI indirectly. 【Conclusion】Legume (peanut) and root crop (sweet potato) rotations with wheat-maize rotations could significantly improve soil quality and enhance the soil nutrient supply capacity in the NCP.

【Objective】Based on whole genome identification and analysis of soybean LOX gene family members, to understand the taxonomic evolutionary relationships of each member, to study the expression specificity of each gene member in different tissues and their response to abiotic stress, which provided a theoretical basis for further research on the molecular characteristics, evolutionary process, and function of the LOX gene family. 【Method】Based on the LOX protein sequences of rice and Arabidopsis species in Ensembl database, BLASTP alignment of homologous LOX protein sequences in soybean whole genome database was performed, and MEGA X software was used to construct a phylogenetic tree; Using website MEME for protein conserved motif analysis; Using online software GSDS 2.0 to analyze gene structure; Using TBtools for chromosome localization drawing; Analyze soybean LOX family replication genes using McscanX; Using the PlantCARE website to predict the promoter elements of soybean LOX gene family; Draw gene expression heatmaps of soybean under different tissues and abiotic stress using TBtools, and develop molecular markers for the excellent allele variant GmLOX15A1^-G/A significantly correlated with 100-seed weight.【Result】A total of 43 LOX genes were identified in soybean, unevenly distributed on 13 chromosomes. Collinearity analysis indicates that the GmLOX gene has undergone extensive replication during the evolutionary process. Meanwhile, 39 different types of cis regulatory elements were detected in the LOX gene promoter, indicating that they may be involved in different pathways such as growth and development, light response, stress response, and hormone induction. Expression pattern analysis revealed that the LOX gene has different levels of expression in different tissues of soybean, indicating that members of this family have tissue and spatiotemporal expression specificity. Under drought stress conditions, the GmLOX gene was significantly differentially expressed in soybean roots and leaves (P<0.05). Among them, GmLOX3A3, GmLOX7A1, GmLOX20B1, GmLOX13A1, and GmLOX20A2 were significantly upregulated or downregulated in roots and leaves, suggesting that the GmLOX gene may play an important role in response to stress. At the same time, it was found that GmLOX15A1 is highly expressed in grain tissue and there is an excellent G/A allele variation in the seventh exon of the gene coding region. Molecular markers were developed for this variant site, and the correlation between different haplotypes of GmLOX15A1 and 100-seed weight was analyzed using 1 200 soybean germplasm resources from different ecological regions over a period of 2 years. The results showed that compared to the GmLOX15A1^-A genotype, the average 100-seed weight of soybean germplasm carrying the GmLOX15A1^-G allele gene increased by 2.33 g (P<0.001). 【Conclusion】A total of 43 members of the LOX family were identified in soybeans, which can be divided into 3 subfamilies. The promoter region of the GmLOX gene contains a large number of cis acting elements that respond to hormones and stress, playing different roles in drought stress response. Among them, GmLOX15A1 is highly expressed in grain tissue and there is an excellent G/A allele variation in the seventh exon of the coding region of this gene. Compared with the GmLOX15A1^-A genotype, the average 100-seed weight of soybean germplasm carrying the GmLOX15A1^-G allele gene is significantly increased by 2.33 g. This locus can be used as an excellent haplotype for genetic improvement of soybean grain size.

【Objective】 This study aims to discover new quantitative trait loci (QTLs) for resistance to the brown planthopper (BPH) in rice by utilizing a genetic population and to assess the pyramiding effects of these QTLs, thereby providing crucial genetic materials and resources for breeding insect-resistant rice. 【Method】 A recombinant inbred line (RIL) population derived from a cross between susceptible NPB and resistant Jiafuzhan was used, combined with seedling stage resistance evaluation and extreme mixed pool sequencing (BSA-seq) to map BPH resistance QTLs. Further, fine mapping, candidate gene identification, pyramiding effect analysis, and mixed-pool transcriptome sequencing (BSR-seq) were employed to elucidate the physiological and molecular mechanisms mediated by these QTLs. 【Result】 BSA-seq identified two major resistance QTLs on chromosomes 1 (30-32 Mb) and 4 (5-7 Mb), named QBPH1 and QBPH4, respectively. Interval-linked molecular markers confirmed the authenticity of these QTLs. QBPH4 coincides with previously cloned BPH3 and BPH15, while QBPH1 represents a newly discovered QTL. High-density markers and recombinant analysis further narrowed the QBPH1 region to 30.61-30.65 Mb. This analysis identified Os01g53294 and Os01g53330 as reliable candidate genes, which code for a respiratory burst oxidase protein B and an anthocyanin 5,3-O-glucosyltransferase, respectively. In evaluations of seedling resistance, brown planthopper honeydew area and weight, insect weight gain, lethality, and preference, comparisons between QBPH1 and QBPH4 single genes and their polymerized lines revealed no significant enhancement in resistance. Both QBPH1 and QBPH4 mediated antibiosis and antixenosis mechanisms with varying effects. BSR-seq analysis highlighted significant enrichment of differentially expressed genes (DEGs) involved in transcriptional regulation, protein phosphorylation, and redox processes among different QBPH1 alleles. Additionally, genes associated with jasmonic acid (JA) synthesis and signaling pathways were significantly upregulated in resistant materials, confirmed by RT-qPCR experiments. 【Conclusion】 A novel BPH resistance QTL, QBPH1, was successfully identified on chromosome 1 of rice. QBPH1 mediated both antibiosis and avoidance against BPH, though its aggregation effect with another QTL was not significant. QBPH1 may mediate defense mechanisms against BPH through involvement in the JA pathway. Based on this, Os01g53294 and Os01g53330 have been validated as reliable candidate genes for QBPH1.

【Objective】Polymerizing soybean high oil genotypes aims at breeding varieties with higher oil content to improve economic efficiency and nutritional value. It is of great significance to increase agricultural output, reduce processing costs and meet global demand for vegetable oil growth.【Method】Glyma.18G027100 C2 gene family was identified by bioinformatic analysis method at the whole genome level. A total of 66 soybean C2 gene family members were identified, named GmC2-01.1-GmC2-20.2 according to chromosome position. Tissue pattern analysis revealed that 7 genes were highly expressed in grains among 66 C2 family genes (GmC2-03.6, GmC2-02.7, GmC2-07.2, GmC2-18.1, GmC2-18.4, GmC2-19.1 and GmC2-20.2). In order to analyze the effect sites of these genes on soybean oil content, SNP sites in the coding regions of these genes were obtained from SFGB database. Correlation analysis of oil content in two years showed that GmC2-18.1 has SNP loci that significantly affect oil content. The genetic diversity of GmC2-18.1 coding region was analyzed by 12 extreme materials. There was a G/A mutation at 2 038 273 bp in coding region of Wm82.a2.v1 version, which regulated seed oil content. It was preliminarily speculated that this gene played a role in seed development or nutrient accumulation. Then, SNP/InDel molecular markers were developed for GmC2-18.1^-G/A gene combined with InDel natural allelic variation site 225 bp upstream of the start codon of GmSWEET39, T/C natural allelic variation site at 8 381 058 bp in coding region of GmST1, A/C natural allelic variation site at the third exon of 41 854 422 bp in coding region of GmMFT. 1 200 soybean germplasm resources from three ecological regions in China were identified by markers in 2 years.【Result】Analysis of variance showed that GmC2-18.1^-G, GmSWEET39^-Deletion, GmST1^-T and GmMFT^-A significantly increased oil content by 1.72, 1.95, 1.58 and 2.06 percentage points (P<0.01). The results showed that the average oil content of soybean seeds carrying GmC2-18.1^-G, GmSWEET39^-Deletion, GmST1^-T and GmMFT^-A high-oil allele type (PFAT-1) was 22.89%, which increased by about 4.5% compared with that carrying GmC2-18.1^-A, GmSWEET39^-Insertion, GmST1^-C and GmMFT^-C low-oil allele type (PFAT-14). 5 percentage points, the contribution rate to oil content is about 21.69%. 【Conclusion】Based on the markers developed above, 115 PFAT-1 high oil alleles were screened.

【Objective】 Grain size and weight are the important factors affecting the yield of maize. The EIN3/EIL gene family is a sort of key transcription factors in the ethylene signaling transduction pathway, and the functions and regulatory mechanisms of the EIN3/EIL gene ZmEIL9 were analyzed in maize kernel development to elucidate its molecular mechanisms.【Method】 The expression patterns of ZmEIL9 in maize kernel at different developmental stages were analyzed by bioinformatics and RT-qPCR. The multiple sequence alignment of ZmEIL9 and its homologs from different species was performed, and the phylogenetic trees was constructed based on the neighbor-joining method. The sequence characteristics of ZmEIL9 protein were analyzed, and subcellular localization of ZmEIL9 was performed. The insertion mutants of Mu transposon and CRISPR/Cas9 knockout mutants of ZmEIL9 were screened, and the agronomic traits including grain filling rate, storage substances such as starch granule and protein content were analyzed. 【Result】 According to the members of EIN3/EIL family in maize, phylogenetic trees showed that ZmEIL9 was closely related to ZmEIL1 and SbEIL1. In the transcriptomic database of maize inbred line B73, the expression levels of ZmEIL9 were higher in the grain at early and late developmental stages. However, the expression levels were higher in inbred line N04 at the middle and late developmental stages. ZmEIL9 encoded 644 amino acids in the inbred lines Dan232 and N04, while its homolog in inbred line B73 has 642 amino acids. Subcellular localization analysis indicated that ZmEIL9 was localized in nucleus. The ZmEIL9 mutants with different Mu transposon insertion sites and CRISPR/Cas9 knockout mutants with amino acid frameshift mutations were obtained, respectively. The plant height, grain length, and 100-grain weight of Mu mutants and knockout mutants were significantly lower than those of its wild counterpart. The grain dry weights at different developmental stages were also analyzed, and the grain filling rates of Zmeil9 mutant were lower than those of the wild type. The starch granules of Zmeil9 mutant were significantly smaller and had an irregular shape based on scanning electron microscopy (SEM) observations. The contents of total starch and the concentration of zein protein in the Zmeil9 mutant were significantly lower than those in the control. 【Conclusion】ZmEIL9 plays an important regulatory role in the kernel development of maize.

【Background】To determine the safe planting limit of winter wheat based on agricultural climate indicators is crucial for the scientific and rational utilization of resources, avoiding freezing disasters, and ensuring stable and high yields of winter wheat. However, in the north of China, which is located in the sensitive area of winter wheat planting, the fluctuation of safe winter wheat planting has been intensified due to the increase of extreme weather events caused by global climate change. It is urgent to clarify the agroclimatic factors affecting the safe planting of winter wheat on a large regional scale and to determine their threshold ranges. 【Objective】The research on the agricultural climatic factors and their thresholds for the safe planting of winter wheat was conducted to provide a scientific basis for the sustainable production and planning of winter wheat in response to climate change. 【Method】The northern China was selected as the research area, which was highly sensitive to the safe planting of winter wheat. Based on the spatial distribution of winter wheat with medium and high spatial resolution and ground meteorological observation data, this research utilized methods such as kernel density estimation, geographic detector to reveal the spatial pattern characteristics of the actual northern limit of winter wheat planting, to quantitatively analyze the influence of agricultural climate factors on the formation of the actual northern limit of winter wheat planting, and to explore the threshold of key climate factors. 【Result】(1) The actual northern limit of winter wheat planting, with a total length of about 2 200 km, fluctuated from southwest to northeast. However, agricultural climate factors exhibited more significant fluctuations along the line of Pingning-Xunyi-Tongchuan-Baishui- Heyang-Hancheng-Jishan. (2) The negative accumulative temperature during winter, average temperature of the coldest month, extreme minimum temperature of the year, and accumulative temperature before winter were crucial factors (q >0.45) in shaping the actual northern limit of winter wheat planting. Agricultural precipitation factors had a minor effect (q <0.19) on winter wheat planting, but interacted strongly with temperature factors (q >0.57). (3) Specific meteorological parameters for the northern limit of winter wheat safe planting in northern China were established: negative accumulated temperature in overwintering period≥-620 ℃·d, coldest monthly mean temperature≥-8 ℃, annual extreme minimum temperature≥-22 ℃, and accumulated temperature before overwintering≥529 ℃·d. (4) The potential northern limit for winter wheat planting has moved about 107 km northward compared to the actual limit, with approximately 23.39×10³ km² of expansion area. 【Conclusion】This study identified the key agricultural climate indicators and thresholds influencing safe winter wheat planting in northern China, which provided a basis for determining potential safe planting areas for winter wheat. The research results could provide the theoretical reference and technical support for how winter wheat planting could adapt to climate change and adjust agricultural planting layout reasonably.

【Objective】 The essence of conventional wheat breeding involves the continuous multi-generation selection and maintenance of hybrid F₁ trait heterosis. Exploring the heterosis and combining ability of lodging-related traits among spring wheat varieties (lines) in the Yellow River irrigation area of Ningxia, and clarifying significantly agronomic indexes related to anti-lodging traits in wheat that can provide a certain theoretical basis for utilizing heterosis in lodging traits of spring wheat, and for the screening and maintenance of its descendants in Ningxia.【Method】 This study utilized 14 spring wheat varieties (lines) from Ningxia Yellow River Irrigation Area as parent materials. According to NCⅡ incomplete diallel crossbreeding design, forty-five combinations were produced. Meanwhile, heterosis, combining ability, and correlation analyses were performed on 13 traits related to lodging resistance, such as plant height and culm type index, in their parents and their F₁ generation.【Result】 Significant differences in lodging resistance trait were observed among different spring wheat varieties (lines). Meanwhile, there is a certain level of heterosis in lodging resistance traits was evident in the F₁ generation. The main stem thrust resistance of NZ42, M6445, and M8887 showed high general combining ability (GCA) values of 11.68, 8.00, and 10.67 respectively. Significant combinations for main stem thrust resistance included M6445×M8887, M6445×MJ48, NZ42×N2038, NZ42×M7723, NZ42×NZ39, and H3015×Ningchun50. Correlation analysis revealed that plant height was significantly positively correlated with the first internode length and second internode weight, and highly significantly positively correlated with the second and fourth internode lengths. Besides, the main stem thrust resistance was highly significantly positively correlated with fresh weight of the main stem, stem diameter, bending moment and culm type index, but significantly negatively correlated with the fourth internode length. However, it was not significantly correlated with the second internode weight and fullness.【Conclusion】 The excellent parent varieties identified were NZ42, M6445, and M8887. Meanwhile, the excellent combinations of NZ42 × NZ39, M6445 × MJ48, and M6445 × M8887 were also observed in this study. In addition, Heterosis was present among most lodging resistance traits in different combinations, but the heterobeltiosis was less pronounced. The resistance to lodging was influenced by both additive and non-additive effects of parental genes, with a greater influence from the maternal genetic background. Furthermore, the plant height and main stem thrust resistance are significantly correlated with the fourth internode length, bending moment, and culm type index, serving as important references for selection of lodging-resistant generations.

【Objective】 Rice blast is one of the main diseases that threaten rice yield and quality. OsBSK1-2 has been found to be involved in rice blast resistance regulation. Previously, OsCBSX4, a cysteine sulfide-β-Synthase, was identified by screening the proteins that interact with OsBSK1-2. The purpose of this study was to verify the interaction between OsBSK1-2 and OsCBSX4, and clarify the function and molecular mechanism of OsCBSX4 in rice blast resistance, providing a theoretical basis for rice disease resistance breeding.【Method】 Co-immunoprecipitation, bimolecular fluorescence complementation and luciferase complementation assays were used to determine the interaction between OsBSK1-2 and OsCBSX4. Then, quantitative PCR and agrobacterium- mediated transient transformation in N. benthamiana were used to detect the gene expression pattern and protein localization of OsCBSX4. Subsequently, OsCBSX4-knockingout and OsCBSX4-overexpressing plants were generated via CRISPR/Cas9 technology and Agrobacterium-mediated genetic transformation, respectively, and their resistance to rice blast was determined by inoculation with M. oryzae. Moreover, the immune responses induced by chitin and M. oryzae in the oscbsx4 mutant were analyzed using ROS burst and DAB staining assays respectively. In the end, the interaction between OsCBSX4 and OsRbohB was verified via bimolecular fluorescence complementation and split-luciferase complementation imaging assays, and the impact of the metabolite of OsCBSX4 on rice blast resistance was determined using the detached leaf inoculation method. The studies above will reveal the immune function and molecular mechanism of OsCBSX4.【Result】 The interaction between OsCBSX4 and OsBSK1-2 was verified by CoIP, LCI and BiFC assays. Compared to the wild type, the oscbsx4 mutant showed more disease lesions after inoculation with M. oryzae by the spray method, as well as a larger lesion area and greater fungal growth after inoculation with M. oryzae by the punch method, suggesting that knocking out OsCBSX4 decreased rice blast resistance. Moreover, the expression of the pathogenesis-related genes, OsPR5 and OsPR10, and the H₂O₂ accumulation induced by M. oryzae infection and the ROS burst induced by chitin treatment were reduced in the oscbsx4 mutant. Compared with the wild type, OsCBSX4 overexpressing plants showed a smaller lesion area and less fungal growth after inoculation with M. oryzae by the punch method, suggesting that overexpression of OsCBSX4 increased rice blast resistance. In addition, we found that OsCBSX4 can interact with OsRbohB, a key regulator of rice ROS production and treating rice with L-cysteine, a metabolite of OsCBSX4, does not affect rice blast resistance. 【Conclusion】 OsCBSX4 is an important component of OsBSK1-2 signaling and positively regulates rice blast resistance. OsCBSX4 may mediate ROS production by interacting with OsRbohB, thereby regulating rice immunity.

【Objective】Branching is a significant factor influencing alfalfa yield, and the SPL family of transcription factors represents a crucial class of regulatory genes involved in branching (tillering) development in a diverse range of plants. The objective of this reserch is to investigate the biological function of MsSPL17 in alfalfa and to elucidate the role of MsSPL17 in regulating the development of alfalfa meristems. This will provide a valuable reference for alfalfa high-yield biological breeding.【Method】Bioinformatics methods were used to anlyze MsSPL17 sequences and also constructing a phylogenetic tree. The tissue expression specificity of MsSPL17 in alfalfa was analyzed by real-time fluorescence quantitative PCR (qPCR). The subcellular localization of MsSPL17 protein was determined by tobacco transient expression system, and the transcriptional self-activation activity of MsSPL17 was verified. The transgenic alfalfa was obtained by Agrobacterium-mediated transformation and phenotypic analysis was carried out. Transcriptome analysis was utilized to screen for differentially expressed genes in transgenic lines and validate them for further research.【Result】MsSPL17 contained an open reading frame of 1 011 bp, encoding a protein composed of 366 amino acids, belonging to the SBP protein family. Phylogenetic analysis showed that the evolution of MsSPL17 and its homologous genes was highly similar to the differentiation of species, indicating that it is a functional conserved gene. MsSPL17 expressed in all tissues, including stems, nodes, leaves and tops during the critical period of alfalfa growth and development, implied the necessary regulating function of this gene in alfalfa branching. Subcellular localization assay showed that MsSPL17 protein was localized in the nucleus. Transcriptional self-activation assay showed that MsSPL17 did not have self-activation activity and could be used in interacting proteins screening. MsSPL17 transgenic silenced lines exhibited a notable phenotype, including an increase in branch number and stem node number, a reduction in internode length, and an enhancement in nutritional quality.【Conclusion】MsSPL17 was successfully cloned, it expressed in key tissues of alfalfa branching development. The protein encoded by MsSPL17 was localized in the nucleus and demonstrated no transcriptional self-activation activity. Transgenic lines exhibiting multi-branching traits were obtained, and the number of branches increased significantly in yield, while the crude protein content increased in quality.

Gene editing techniques have made gene edited (GE) organisms enter commercial applications from laboratories. In 2022, the Ministry of Agriculture and Rural Affairs specifically issued the “Guidelines for Safety Evaluation of Genetically Edited Plants for Agricultural Use (Trial)” for the safety evaluation of GE plants without introducing exogenous genes. In 2023, China granted the first biosafety certificate for GE soybean AE15-18-1, marking the official start of the commercialization process of GE crops in China. GE organisms are different from traditional genetically modified organisms (GMOs) containing exogenous DNA sequences, making common GM detection strategies inapplicable to the detection of GE organisms. As the industrialization of GE crops progresses positively, how to efficiently and accurately detect whether a product is gene-edited and its editing characteristics is an important basis for the commercial use and intellectual property protection of GE products. There is an urgent need to develop detection technologies suitable for GE products. With the goal of detecting whether the target sequence has been edited, many detection technologies have been developed based on PCR, sequencing, and other technologies, and are widely used in the screening of GE products in the research and development process. After industrialization, safety supervision and intellectual property protection require not only the detection of whether the sample has been edited but also the rapid identification of the nucleotide sequence characteristics of the sample to determine its origin and identity. Subsequently, precise quantification of the GE components is necessary to determine whether quantitative labeling is required. Currently, it is difficult to quickly identify the identity of GE products with only a few base insertions, deletions, and single nucleotide variations (SNV) using conventional PCR or sequencing technologies. It is even more challenging to accurately quantify the content of GE components. Aiming at the rapid identification of the DNA sequence characteristics after editing and precise quantification, based on the molecular characteristics of GE products, this paper reviews the application of the gel electrophoresis-based PCR method, the sequencing-based method, the real-time PCR-based method, the digital PCR-based method, the editing enzyme-based method, and the instrument-based method in detection of GE organisms, and expounds the advantages and disadvantages of each method during detection. This review initially explores the detection and quantification strategies suitable for GE organisms and provides a reference for subsequent development of detection methods for GE organisms.

【Objective】The GRAS family constitutes a unique class of plant-specific transcription factors that play a pivotal role in plant development and stress response. To elucidate the function of GRAS family genes in wheat heat tolerance，which can provide genetic resources and theoretical foundation for wheat heat-resistant breeding.【Method】A potential heat stress-responsive transcription factor gene, TaGRAS34-5A, was identified through transcriptome analysis of TAM107 and Chinese spring wheat seedlings under high-temperature conditions. Subsequently, a bioinformatics analysis was performed on TaGRAS34-5A, and a phylogenetic tree was constructed to elucidate its molecular characteristics. The expression pattern of TaGRAS34-5A under various stresses, including high temperature, abscisic acid (ABA), ethylene (ETH), and salicylic acid (SA) treatments, were examined using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) method. The subcellular localization of the TaGRAS34-5A protein was determined using wheat protoplast transient expression technique. Furthermore, the heat tolerance function of TaGRAS34-5A was validated using the heterologous expression system of Saccharomyces cerevisiae and the BSMV:VIGS (Barley stripe mosaic virus: Virus-Induced Gene Silencing) silencing technique. potential interacting proteins of TaGRAS34-5A were screened using yeast two-hybrid technology, and the heat tolerance function was verified, providing preliminary insights into its heat tolerance mechanism.【Result】TaGRAS34-5A, equipped with a characteristic GRAS domain and belongs to the GRAS transcription factor family, is localized to both the cell nucleus and cytoplasm. Bioinformatics analysis indicates that the TaGRAS34-5A promoter contains a large number of hormone response elements and light response elements, and it is most closely related to TaSCL14, OsGRAS23, and AtSCL14 in terms of phylogenetic relationships, suggesting its potential function in responding to oxidative stress. Its expression is upregulated under high-temperature, ethylene (ETH), abscisic acid (ABA), and salicylic acid (SA) treatments, peaking at 4, 6, 0.5, and 12 hours post-treatment, respectively, with the most significant induction observed under heat stress and SA. Functional assays in yeast demonstrated that heterologous expression of TaGRAS34-5A enhances the heat tolerance of the yeast. The results of BSMV:VIGS transient silencing experiment showed that after the 42 ℃ high-temperature treatment, TaGRAS34-5A silenced plants exhibited decreased chlorophyll content, reduced POD enzyme activity, increased cellular peroxidation, and decreased heat tolerance compared to the control. Preliminary studies on the heat tolerance mechanism suggest that TaGRAS34-5A exhibits strong transcriptional self-activation activity.it may modulate wheat heat tolerance by interacting with proteins such as the bZIP family transcription factor HBP-1b and the E3 ubiquitin ligase hel2, thereby regulating cellular redox homeostasis and detoxification processes, positively influencing the heat tolerance of wheat.【Conclusion】TaGRAS34-5A is induced by heat, ABA, ETH, and SA, and its encoded protein is located in the nucleus and cytoplasm. It exhibits transcriptional activation activity. Heterologous overexpression of TaGRAS34-5A enhances the heat tolerance of Saccharomyces cerevisiae. Silencing TaGRAS34-5A in wheat plants increases cellular peroxidation, decreases chlorophyll content, and reduces heat tolerance. TaGRAS34-5A may regulate the heat tolerance of wheat by modulating cellular redox state and detoxification processes.

【Objective】 Jasmonic acid (JA) is one of key regulatory hormones during potato tuber development. Study on JA regulating tuber development mechanism would provide an important theoretical basis for tuber yield and quality formation.【Method】 In this study, potato stolons cultured in vitro were exogenously applied with JA (0, 0.5, 5, 50 μmol·L^-1) to analyze the phenotype, tissue microstructure, carbohydrate accumulation and proteome change of tubers.【Result】 With the increase of JA concentration, the tuber number formed per stolon, tuber diameter, fresh and dry weight, cell area of perimedullary zone, starch and soluble sugar content were gradually increased at 0.5 and 5 μmol·L^-1 JA (P<0.05), whereas the tuber diameter, fresh and dry weight, starch content were significantly decreased at 50 μmol·L^-1 JA (P<0.05). Lipoxygenase activity was gradually decreased with JA concentration increasing (P<0.05). Thirty-five differentially abundant proteins (P<0.05 and fold change≥2.5) closely related to tuber development regulating by JA were identified by 2-DE and MALDI-TOF/TOF-MS. They were mainly involved in bioenergy and metabolism (28.6%), cell defense and rescue (28.6%), protein biogenesis and storage (11.4%), signaling (8.6%), transcription (8.6%), unknown (8.6%) and miscellaneous (5.6%). The differential expression patterns of these proteins were clustered into three categories by hierarchical clustering analysis. Cluster 1 included 17 proteins that down-regulated at 0.5 μmol·L^-1 JA and up-regulated at 5 μmol·L^-1 JA, which mainly involved in bioenergy and metabolism, protein biogenesis and storage, signaling and transcription. Cluster 2 included 10 proteins that gradually up-regulated with JA concentration increasing, which were mainly involved in cell defense and rescue, bioenergy and metabolism, transcription. Cluster 3 included 8 proteins that down-regulated after JA treatments, which were mainly involved in bioenergy and metabolism, cell defense and rescue, protein biogenesis and storage. 【Conclusion】 Low JA concentration (0.5, 5 μmol·L^-1) might promote tuber morphogenesis by inducing cell enlargement in tuber perimedullary zone, intracellular sucrose and polysaccharide accumulation, and cell defense ability, whereas high JA concentration (50 μmol·L^-1) showed inhibitory effects.

【Objective】In order to explore the adaptability of 10 oat (Avena sativa) varieties in the Qinghai Lake area and screen out the high-yield and high-quality oat varieties suitable for planting in this area, so as to provide data support for high-yield and high-quality forage production in this area and similar areas. 【Method】In this study, 10 oat varieties (Avena sativa cv. Qinghai No.444, A. sativa cv. Baiyan No.7, A. sativa cv. Qingyan No.4, A. nuda cv. Qingyou No.3, A. sativa cv. Qingyin No.2, A. sativa cv. Qingyan No.3, A. sativa cv. Lena, A. sativa cv. Qinghai, A. sativa cv. Qingyan No.1 and A. sativa cv. Longyan No.1) commonly cultivated in Qinghai province were used. The experiment was established using a randomized complete block design. Three experimental blocks, located at least 3 m away from each other, were randomly chosen. Each block contained 10 different oat varieties plots, for a total of 30 plots. The area of each plot was 3 m × 5 m. The experiment was sown in strip. The row spacing was 25 cm and the sowing depth was 3-4 cm. According to the thousand seed weight, purity and germination rate of each variety, the seeding rate of each variety was calculated according to the seedling protection number of 6.75 million plants/hm². Moreover, the diammonium phosphate (150 kg·hm^-2) and urea (75 kg·hm^-2) were used as base fertilizer. The seeds were sown on May 16, 2022 and May 19, 2023, and field observations and sample collection were conducted on September 23, 2022 and September 26, 2023, respectively. The production performance and nutritional quality of oat varieties were analyzed, and the piecewise structural equation model was used to explore how varieties, planting years and their interactions affected nutritional quality via agronomic traits and yield traits. Furthermore, the multi-criterion decision model-TOPSIS (Technique for order preference by similarity to an ideal) was used to comprehensively evaluate the various indexes of the tested oat varieties. 【Result】Our results demonstrated that A. sativa cv. Qingyan No.3 had the highest plant height (89.4-92.5 cm), and the lowest acid detergent fiber (34.8%-34.9%) and neutral detergent fiber (51.8%-53.4%). The A. sativa cv. Qingyan No.4 had the most tillers number (2.7-3.6/plant) and the lowest crude ash content (10.9%-11.3%). The highest of forage yield, crude protein, relative feeding value were found in A. sativa cv. Qingyan No.3 and A. sativa cv. Qingyan No.4. while the stem/leaf ratio of the A. sativa cv. Qingyan No.3 and A. sativa cv. Qingyan No.4 were significantly lower than that of other varieties. The highest crude fat was found in A. sativa cv. Qingyan No.1 (3.8%-3.9%). The Pearson correlation analysis showed that the oat yield was positively correlated with crude protein content and relative feeding value, but negatively correlated with acid detergent fiber and crude ash. The stem/leaf ratio was positively correlated with acid detergent fiber and neutral detergent fiber, but negatively correlated with crude protein and relative feeding value. The structural equation model analysis showed that the varieties, planting years and their interactions had direct effects on the oat nutritional quality, and indirectly affected the nutritional quality by affecting plant height, tillering number, stem/leaf ratio and hay yield. The total effect value of stem/leaf ratio was the highest, which was -0.37.【Conclusion】The comprehensive evaluation of TOPSIS model showed that A. sativa cv. Qingyan No.4 and A. sativa cv. Qingyan No.3 could not only maintain higher production performance, but also have higher nutritional quality, which are ideal oat varieties for planting in Qinghai Lake area.

【Objective】The analysis of rice yield, nitrogen use efficiency and the quantitative relationship between apparent nitrogen balance and soil alkali-hydrolyzed nitrogen under different nitrogen fertilizer management conditions could provide a more comprehensive understanding of the effects of long-term fertilization on soil fertility, so as to provide the theoretical guidance for efficient production and scientific nitrogen management of red soil paddy fields. 【Method】Based on the red soil double cropping rice long-term fertilization positioning experiment (started in 1981, located in Jinxian County, Jiangxi Province), five treatments were selected: no fertilizer (CK), nitrogen and phosphorus fertilizer (NP), nitrogen and potassium fertilizer (NK), nitrogen, phosphorus and potassium fertilizer (NPK), nitrogen, phosphorus and organic fertilizer (NPKM), and then the grain and straw yield and nitrogen uptake of rice in each season were investigated and analyzed, and the soil alkali-hydrolyzed nitrogen content was analyzed after late rice. The nitrogen uptake, nitrogen utilization rate, nitrogen apparent balance and the changes of soil alkali-hydrolyzed nitrogen were calculated and analyzed on a 10-year basis. 【Result】During the 40 years of experiment (1981-2020), the rice yield and nitrogen uptake under NPKM treatment were the highest, increased by 65.9%-108.4% and 85.1%-132.5% compared with CK, respectively, and increased by 19.3%-92.1% and 19.4%-99.8% compared with fertilizer treatments (NPK, NK and NP), respectively, showing significant differences. With the increase of the experimental period, the nitrogen use efficiency of fertilizer treatment gradually decreased, and the NPKM treatment also showed a decreasing trend in the first 30 years (1981-2010), but the rate was slower than that of fertilizer treatment, and increased in the recent 10 years (2011-2020), and from the lowest in the first 10 years (1981-1990) to the highest in the recent 10 years, increased by 25.3%-271.2% compared with fertilizer treatment. The nitrogen surplus was the highest under NPKM treatment during the 40 years of experiment, with an increase of 137.1%-577.2% compared with fertilizer treatment, but in the last 30 years (1991-2020), the nitrogen surplus gradually decreased with the increase of the experimental period. The soil alkaline hydrolyzed nitrogen content was the highest under NPKM treatment during the 40 years of experiment, increased by 7.1%-24.4% compared with CK, but the difference was not significant in the first 10 years, and increased by 11.0%-35.2% compared with fertilizer treatment, while there was no significant difference between fertilizer treatment and CK. Correlation analysis showed that the nitrogen surplus was significantly positively correlated with the soil alkaline hydrolyzed nitrogen content in the last 20 years (2001-2020). 【Conclusion】In the red soil double-cropping rice system, with the increase of fertilization years, the combined application of organic and inorganic fertilizers had better effects on rice yield, nitrogen uptake, nitrogen uptake and utilization, and soil alkali-hydrolyzed nitrogen content. Meanwhile, the increase of nitrogen surplus caused by long-term fertilization also further increased the soil alkali-hydrolyzed nitrogen content in the topsoil. The contribution capacity of nitrogen surplus to soil alkali-hydrolyzed nitrogen increased gradually.

【Objective】 Replacing some chemical nitrogen fertilizers with leguminous green manure is an important technical measure to achieve reduced fertilizer application. The effects of hairy vetch which was planted to replace winter wheat and nitrogen reduction on the accumulation and transportation of dry matter accumulation, yield formation, and post flowering leaf senescence characteristics of maize in North China were studied, so as to provide a scientific basis for leguminous winter green manure substitution for chemical nitrogen fertilizer and optimized management of nitrogen resources in maize. 【Method】 The two-factor split plot field experiment was carried out from 2020 to 2022 at Shenzhou Experimental Station of Dryland Farming Institute of Hebei Academy of Agriculture and Forestry Sciences. The two modes, including the winter fallow field (FF) and hairy vetch being planted in the winter fallow field and total returning (HV), were set as main treatment, and the five nitrogen application rates of maize were set as sub-treatment, including no nitrogen application (0 N), 67.5 kg·hm^-2 (25% N), 135.0 kg·hm^-2 (50% N), 202.5 kg·hm^-2 (75% N), and 270.0 kg·hm^-2 (100% N, the conventional nitrogen application level). Yield and yield components, ear agronomic traits, dry matter accumulation and transport, leaf senescence characteristics of maize, and changes in soil nutrients and enzyme activity were investigated, moreover, the nitrogen surplus in farmland were analyzed.【Result】 Returning hairy vetch to the field significantly increased maize yield and could compensate for the reduction in maize yield caused by chemical nitrogen reduction. From 2021 to 2022, the return of hairy vetch dramatically raised maize yield (8.15%-9.21%), which could compensate for the grain yield loss caused by 25%-50% reduction in nitrogen fertilization. Continuous return of hairy vetch significantly reduced the bare top length, dramatically increased the ear length, the ear diameter, and yield components, such as row number, kernels number per row, and hundred-grain weight. After returning hairy vetch to the field, the dry matter accumulation before and after flowering, the dry matter accumulation rate after flowering, and the contribution rate of dry matter after flowering to grains significantly increased by 10.21-12.32 g/plant, 39.94-72.37 g/plant, 4.67%-4.78%, and 3.31%-3.99%, respectively, which could compensate for the negative effect of reducing nitrogen fertilizer application by 25%-50% on the dry matter accumulation before flowering and the contribution rate of dry matter after flowering to grains of maize. The incorporation of hairy vetch prominently postponed the post-anthesis leaf senescence of maize. In 2021 and 2022, the green leaf area of maize treated with HV was 303.44-1 115.10 and 266.23-837.62 cm²/plant higher than that under FF, respectively. The relative green leaf area after flowering increased by 1.12% -13.84% and 0.56% -9.13%, respectively. V_max decreased by 0.30% and 0.05%, respectively. T_max was delayed by 6.01 days and 3.56 days, respectively. The organic matter content, total nitrogen content, alkaline nitrogen content, as well as the activities of urease, sucrase, amylase, and protease in the soil significantly increased after continuous returning of hairy vetch to the field. In 2021 and 2022, the nitrogen rates under HV could increase by 40.92 and 72.79 kg·hm^-2, respectively; the optimal chemical nitrogen applications under HV could be reduced by 40.96 and 48.90 kg·hm^-2, respectively; the nitrogen surplus under HV could be decreased by 7.94 and 0.14 kg·hm^-2, respectively; HV could replace a maximum nitrogen application rate of 15.71% and 19.71%, respectively, which could replace conventional nitrogen application rates of 15.71% and 26.23%, respectively. 【Conclusion】 The incorporation of hairy vetch could activate soil enzyme activity, effectively enhance soil nitrogen nutrient supply capacity, delay post popcorn leaf senescence, increase the contribution rate of post flowering dry matter accumulation to grains, and improve ear traits and coordinate yield composition, which all were beneficial for increasing and stabilizing maize yield after nitrogen reduction. The input of soil nitrogen by hairy vetch was the basis for its partial replacement of chemical nitrogen fertilizer and compensation for the yield loss caused by chemical nitrogen reduction. The use of hairy vetch instead of partial chemical nitrogen fertilizer in the seasonal fallow areas of winter wheat in North China was a sustainable nitrogen reduction measure.

【Objective】High-quality is the primary target for waxy maize breeding. The aim of this study is to screen lines with high general combining ability and excellent hybrids with high-quality traits, which will clarify the breeding potential of these lines from Laos and lay a foundation in breeding high-quality waxy maize varieties.【Method】Using the Maize6H-60K chip, high quality genotype data of 33 waxy maize materials were obtained for cluster analysis. Combined with the iodine staining experiment and molecular detection of waxy genes, these types of waxy genes from early-generation maize lines from Laos were identified. Through the incomplete diallel cross experiment, phenotype identification and combining ability analysis of quality and other traits of 439 combinations were carried out to clarify the breeding potential of waxy maize lines with early generation from Laos. An experiment of quality traits evaluation with multi-person was conducted on these selected combinations with advantages to identify the most promising high-quality waxy maize hybrids. 【Result】Clustering analysis was conducted based on 56 626 high quality SNP, and the results showed that these lines from Laos and domestic materials belong to different branches and can be clearly distinguished. All 23 lines with early generation from Laos were waxy maize, among which 16 lines belonged to the wx-D10 type, three lines belonged to the wx-D7 type, and the other four lines were unknown types. The heritability of quality traits of waxy maize materials from Laos is low, ranging from 0.14 to 0.35, which is suitable for selection in higher generations. The average stewing quality of 439 combinations was significantly higher than that of the control Jingkenuo2000 and Shinuo2, but there was no significant difference from Yunuo7. The general combining ability effects of all quality traits of waxy maize lines F02, F22, F25, and F28 were positive, which could be used to improve quality traits of domestic waxy maize in China. Furthermore, these combinations M02×F02 and M22×F22 were evaluated as excellent in multi-person quality traits evaluation experiments by approximately 86% of all tasters.【Conclusion】These local varieties of waxy maize from Laos have rich genetic variation, with a certain genetic distance from domestic waxy maize inbred lines. There may also exist new alleles of waxy gene in these lines from Laos. In addition, these waxy maize lines from Laos have obvious advantages in quality traits, including waxy quality, pericarp thickness and other traits, which can be used as valuable germplasm for improving the quality traits of domestic waxy maize in China.

【Objective】This study aimed to explore the dynamic change of soil texture and nutrients resulting from 60 years of agricultural cultivation subsequent to the conversion of grassland to cropland in the typical steppe of Xilingol County. It also evaluated whether the 18 years cropland afforestation had effectively mitigated the negative impacts of long-term cultivation on soil particle size distribution and soil nutrients. The research sought to enhance understanding of soil quality evolution during ecological restoration processes in this region and provided a scientific basis for assessing the actual effectiveness of ecological restoration measures. 【Method】Five sites within 60 km² of the study area as replicates were chosen to investigate the particle size distribution, bulk density, and nutrient characteristics within the 0-30 cm soil layer across four land use types, including grassland (GL), cropland (CL) and afforestation land with row spacing of 2 m (AL-2) and 5 m (AL-5). 【Result】(1) The soil particle composition across various land use types included sand (61%-82%), silt (16%-35%) and clay (less than 4%). Notably, the content of silt (2-50 μm) in cropland and afforestation land was significantly lower than that in grassland, whereas the proportion of sand (>50 μm) was markedly higher in comparison to grassland. Further, compared with natural grassland, the cultivation has resulted in a reduction of soil particles smaller than 120 μm and an increase in soil particles larger than 120 μm. However, the afforestation for 18 years has not alleviated the decrease in fine particles (≤120 μm) caused by cultivation. (2) In 0-30 cm soil layer, the composition of soil particle size in each land use type showed uniformity along the soil depth, which reflected poor sorting characteristics and a negative to extremely negative particle size distribution pattern and sharp kurtosis. Among them, the grassland had the smallest mean particle size and the highest fractal dimension. (3) The soil bulk density gradually increased with the increase in soil depth. Nutrient changes were primarily concentrated in the shallow soil layer of 0-10 cm, where cultivation activities led to significantly decrease in soil organic carbon (OC), total nitrogen (TN) and total phosphorus (TP) content. Compared with cropland, the shrubland formed after afforestation did not significantly alter the content of organic carbon and total nitrogen, but significantly reduced the total phosphorus content. (4) It A highly significant positive correlation between soil particle components smaller than 120 μm and soil organic carbon, total nitrogen and total phosphorus was found, which indicated that the decline in soil nutrients was closely linked to the loss of fine soil particles. 【Conclusion】In summary, the long-term conversion of grassland to cropland has led to the degradation of soil physical structure, with the loss of soil fine particles has affected the enrichment of nutrients. Moreover, the effects of afforestation after 18 years on improving soil texture and restoring nutrient levels were not significant.

【Objective】Soybean is a short day crop that is sensitive to photoperiod, and it maybe lead to premature or late flowering when it is planted in different ecological areas. Therefore, in the application of ms1 (male sterility 1) basic population for recurrent selection in different ecological regions, there are problems such as the flowering time unsynchronization between local donor parents and acceptor sterile plants and low introduction rate. The purpose of this study is to construct ms1 basic recurrent population adapted to three ecological regions for improving the probability of flowering time synchronization between donor parents and acceptor sterile plants and reveal the changes of maturity genes E1 and E2 genotypes and phenotype of each population after two rounds of cross-fertilize for providing evidence for improvement of the flowering and maturity time of soybeans.【Method】We used 528 donor parents from different ecological regions and the ms1 basic population as materials. The donor parents were genotyping with the KASP markers of maturity genes E1 and E2 reported by previous research. The donor parents were classified according to E1 and E2 genotypes and mixed with seeds of ms1 basic population respectively, and these populations were planted in different ecological areas according to the suitable genotypes of each region for two rounds of cross-fertilize in two years. Northeast ecological region population was planted in Hulunbuir, Inner Mongolia and Chengde, Hebei, respectively. Huang-Huai-Hai ecological region population was planted in Shijiazhuang, Hebei and Xuchang, Henan. South ecological region population was planted in Guangzhou, Guangdong. Seeds harvested from different ms1 populations were planted in Sanya, Hainan every winter. The flowering and maturity time of donor parents and ms1 basic population were investigated, and the proportions of E1 and E2 genotypes in populations of different region were calculated.【Result】According to genotypes of maturity genes E1 and E2, the donor parents were divided into four groups E1E1/E2E2, E1E1/e2e2, e1e1/E2E2 and e1e1/e2e2 with ratios of 12.1%, 65.0%, 19.3%, and 3.6%, respectively. In the ms1 basic population, the late flowering genotype E1E1/E2E2 had the highest proportion (48.6%), and the flowering time of the population was late, mainly concentrated in 45-51 days. After two rounds of import by cross-fertilize, the percentage of target genotype e1e1/e2e2 increased from 33.0% to 51.6% in Hulunbuir of Northeast China, and the percentage of the e1e1/e2e2 genotype increased from 1.6% to 8% in Chengde. The percentage of target genotype e1e1/E2E2 increased from 18% to 23.1% in Shijiazhuang of Huang-Huai-Hai ecological area, and the percentage of E1E1/e2e2 increased from 12.5% to 30% in Xuchang, respectively. The percentage of E1E1/E2E2 remains above 80% in Guangzhou of South ecological region. The proportion of heterozygous genotypes of target imported genotypes was also increasing in the population. After two rounds of cross-fertilize, there were significant differences in flowering time among ms1 populations of different ecological regions, indicating that phenotypes of different populations also changed with the change of genotype of flowering genes.【Conclusion】Importing genotype of donor parents into the ms1 population based on their genotypes of flowering genes can increase the frequency of suitable genotypes in each ecological region, construct ms1 basic recurrent populations adapted to different ecological regions, increase the probability of flower time synchronization of local donor parents and acceptor ms1 sterile plants, achieve open pollination, gene aggregation and accumulation in soybean, and enrich the genetic diversity of the population, further improve breeding efficiency.

【Objective】Due to the cloudy and translucent appearance characteristics of semi-waxy rice, there is a lack of effective evaluation methods in the industry at present. It is necessary to construct an evaluation method for the appearance quality of semi-waxy, and classify the appearance quality of semi-waxy rice, so as to provide technical support for the standardization and development of semi-waxy rice industry. 【Method】In this study, according to GB/T 15682-2008 "Grain and Oil Inspection of rice, Rice cooking and edible quality sensory evaluation method", the appearance quality score of semi-waxy rice was obtained by artificial evaluation method, and various appearance indexes of semi-waxy rice were measured, including chalkiness, transparency, grain type and color space related indexes. Pearson correlation coefficient, max-relevance and min-redundancy, competitive adaptive reweighted sampling and intersection feature selection methods were used to analyze the relationship between chalkiness, transparency, grain shape and color space related indicators and the appearance sensory score of semi-waxy rice, and select the core indicators that can determine the appearance quality of semi-waxy rice for constructing and verification of semi-waxy rice appearance evaluation model. Finally, the model was used to estimate the overall appearance quality of semi-waxy rice in the Yangtze River Delta region and graded according to the estimated score. 【Result】Through comparing the estimation accuracy and stability of four models, this study found that the semi-waxy rice appearance evaluation model, represented by the equation Y=5.68＋0.17X₄＋0.19X₆-0.03X₉-0.12X₁₀, demonstrated the highest accuracy and stability. This model was constructed using chalk rice transparency (X₄), overall transparency (X₆), chalkiness (X₉), and L*(X₁₀), which were selected by the intersection feature selection method. Notably, this model incorporates the fewest number of indicators, with a coefficient of determination (R²) of 0.86 during model validation and a simulated root mean square error (RMSE) of 0.32. After using this model to estimate the appearance of most of the semi-waxy rice in the three rice-growing areas of the Yangtze River Delta, It was found that the appearance scores of the first 20%, 20%-50%, 50%-90% and last 10% of semi-waxy rice materials in the Yangtze River Delta region in this study were greater than 0.23, -0.48-0.23, -1.68--0.48 and less than -1.68, respectively, which can represent four levels of appearance quality of semi-waxy rice in practical applications: Level 1, Level 2, Level 3, Out of level. At the same time, it was found that there were significant gradient differences in grain type, chalkiness, transparency and color space among different appearance grades of semi-waxy rice, but there were different degrees of crossover between their value ranges.【Conclusion】Using chalk rice transparency (X₄), overall transparency (X₆), chalkiness (X₉), and L*(X₁₀), an effective estimation model of semi-waxy rice appearance could be established: Y=5.68＋0.17X₄＋0.19X₆-0.03X₉-0.12X₁₀. With reference to the scoring range of each appearance grade of semi-waxy rice in Yangtze River Delta region, the appearance of a single semi-waxy rice material can be quickly determined by the appearance estimation score. The evaluation of semi-waxy rice by appearance estimation model is beneficial to take into account the different appearance phenotypes of semi-waxy rice, and can accurately reflect the actual situation of semi-waxy rice appearance.

【Objective】 The objective of this study is to investigate the effects of surface tension, droplet size, and leaf angle on the dynamic wetting and spreading behavior of pesticide droplets on both adaxial and abaxial surfaces of rice leaf, and to provide a basis for realizing the “reduce application and increase efficiency” of rice spraying by regulating the dynamic wetting and spreading behavior of pesticide droplets on the rice leaf surface.【Method】 A full factorial experiment was designed to investigate the dynamic wetting and spreading behavior of single droplet on both adaxial and abaxial surfaces of rice leaf in this study. The Silwet-408 solutions with surface tension of 21.4, 33.2, and 43.7 mN·m^-1 were formulated by adjusting the concentration of Silwet-408 to replace the pesticide solutions. A droplet generator was used to produce the single droplets of 532, 627, 746, 830, and 957 μm. The leaf angles were set as 40°, 65°, and 85°.【Result】 There were significant effects of surface tension, droplet size, and leaf angle on the rate of change of droplet contact angle on the rice leaf surface (P<0.05), and the overall trend of the influences on the adaxial and abaxial surfaces was basically the same; increasing leaf angle or reducing droplet size or lowering surface tension could increase the rate of change of contact angle and promote the wetting and spreading of droplet. Among them, the effect of lowering surface tension was the most significant. When the surface tension was decreased from 33.2 to 21.4 mN·m^-1, which was close to the critical surface tension of rice leaf surface, the rate of change of the contact angle (advancing contact angle and receding contact angle) increased by 7.49 and 6.22 times for the adaxial surface, and 11.13 and 7.61 times for the abaxial surface, and the wettability of the droplets was changed from relatively poor or poor (80°≤contact angle<100° or contact angle≥100°) to medium or positive (60°≤contact angle<80° or contact angle<60°) within 75 s; when the surface tension was much larger than the critical surface tension of rice leaf surface, the rate of change of contact angle increased with the increase of leaf angle, and increased with the decrease of droplet size, but the effect of leaf angle was less than that of droplet size, and droplets of almost all particle sizes still maintained relatively poor or poor wettability (80°≤contact angle<100° or contact angle≥100°) after 75 s. In addition, the analysis of droplet wetting hysteresis phenomenon showed that the roughness of the rice leaf surface was relatively small, and the droplet wetting hysteresis phenomenon was not serious. The droplet with surface tension close to the critical surface tension of rice leaf was driven by the dynamic surface tension of the solid-liquid-gas three-phase system to wet and spread on the leaf surface, and the dynamic change of the contact angle with time could be fitted by the model θ=θ_e+Aexp(-Kt); although the droplet with a surface tension much higher than the critical surface tension of rice leaf could steadily adhere to the leaf surface without the phenomenon of roll-off, it was never able to break through the pinning effect and retention resistance of the leaf surface, and could not achieve wetting and spreading.【Conclusion】 All three factors, surface tension, droplet size, and leaf angle, significantly affect the dynamic wetting and spreading behavior of pesticide droplets on the rice leaf surface. In the actual application scenarios, since the leaf angle cannot be adjusted artificially, the surface tension and droplet size of the pesticide solution can be adjusted according to the purpose of the application to regulate the dynamic wetting and spreading behavior of the droplet. The results of this study are helpful to understand the mechanism of dynamic wetting and spreading of pesticide droplet on the rice leaf surface, and can provide theoretical support and guidance for the rational selection of surface tension and droplet size in rice pesticide application scenarios.