【Objective】 To elucidate the causes of high-temperature stress inducing rice floret infertility, the present study analyzed the effects of high-temperature stresses on pollen release related traits including pollen grain swelling, anther dehiscence, pollen grain residue in anther and pollen grain deposition on the stigma of the differential genotypes Indica at anthesis. 【Method】Indica germplasms were sown in batches and cultivated in the Nanchang region, Jiangxi Province, China. The rice plants flowering at natural high-temperature environments on early August with 36.5-37.8 ℃ canopy temperature was used as treatments, and the rice plants flowering at suitable environments on middle September with 30.8-32.5 ℃ canopy temperature were used as controls. The pollen release related traits, such as pollen grain swelling, anther dehiscence, pollen grain residue in anther and pollen grain deposition on the stigma from treatments and controls, were detected and analyzed. 【Result】 After flowering under high-temperature stress, the rice germplasms Jiangxijiansimiao, Yuexiangzhan and Huangguangyouzhan show high-temperature tolerant at anthesis, and the floret fertility rates are 91.6%, 89.2% and 87.9%, respectively; while the germplasms Zhenfu, Yuzhenxiang, IR64 and Miyang46 show high-temperature sensitive at anthesis, and the floret fertility rates are just 55.2%, 60.3%, 61.1% and 73.2%, which are very significantly or significantly lower than that of its corresponding controls. Under high-temperature environments, the pollen grain swelling rates for the high-temperature sensitive germplasms Zhenfu, Yuzhenxiang, IR64 and Miyang46 are just 1.99%, 1.16%, 1.12% and 2.70%, which are very significant smaller than that of its corresponding controls; while the pollen grain swelling rates of the other germplasms show no significant difference between treatment and its corresponding control. Under high-temperature environments, the rates of anther dehiscence length in total anther length for the high-temperature sensitive germplasms Zhenfu, Yuzhenxiang, IR64 and Miyang46 are respective 66.0%, 45.4%, 48.7% and 63.6%, which are very significantly or significantly shorter than that of the corresponding controls, and the pollen grain residue are obvious more than that of the corresponding controls; while the anther dehiscence length rates and the pollen grain residue from the other germplasms show no significant difference between treatments and controls. After flowering under high-temperature environments, the average pollen grain number deposited on one stigma of the sensitive germplasms were about 20, which were significant less than that of the controls; while the average pollen grain number deposited on one stigma of the other rice germplasms show no significant difference between treatments and controls. 【Conclusion】 The high-temperature stresses inhibit the pollen grain swelling, effect the anther normal dehiscence, increase the pollen viscidity to impede the pollen grain releasing from anther and decrease the pollen grain number scattering on the stigma, inducing rice floret infertility and decreasing the seed set.
【Objective】 Chlorophyll, as the core pigment of plant photosynthesis, directly affects the photosynthetic efficiency and yield of plants. By mining molecular markers and candidate genes related to chlorophyll in Sea-island cotton, we can provide a theoretical basis for the improvement of Sea-island cotton varieties. 【Method】 Using 203 sea-island cotton varieties as research objects, the chlorophyll content of sea-island cotton in three stages (budding stage, flowering stage, and boll stage) was measured in 4 environments (2 points in 2 years), and the chlorophyll content of sea-island cotton in 4 environments was measured. Correlation analysis was performed on the chlorophyll content, and the whole-genome resequencing data and the BLUP value of the chlorophyll content were used for genome-wide correlation analysis to screen candidate genes related to chlorophyll content. 【Result】 Descriptive statistics of chlorophyll content in the four environments showed that the chlorophyll content at bud stage, flowering stage and bell stage were normally distributed across years and locations, indicating that the trait is a quantitative trait controlled by multiple genes. Chlorophyll content varied significantly across growth periods and was significantly affected by environment, with correlation coefficients of 0.021-0.287 for chlorophyll content at bud stage, 0.017-0.180 at flowering stage and -0.118-0.212 at bell stage. GWAS research results screened out a total of 52 significant SNPs sites. Among them, 20, 20 and 12 significant SNP sites were screened in the bud stage, flowering stage and boll stage respectively, mainly distributed on chromosomes such as A05, A06, D05, D06 and D10. By annotating significant sites, a total of 80 candidate genes were annotated, including GB_A05G0103, GB_A05G0104, GB_A05G0105, GB_A05G0106, GB_A05G0107, GB_A05G0108, GB_A05G0109, GB_A05G0110, GB_A05G0111 and GB_A 05G0112 and other 10 genes are in type I (4 environments) The flowering stage and the flowering stage of type Ⅱ (two environments in northern Xinjiang) are all annotated. GB_A06G1512 and GB_A06G1513 are annotated in the flowering stage and boll stage of typeⅠand the flowering stage of typeⅡ. GB_D09G0836, GB_D09G0837 and GB_D09G0838 are annotated in the florescence and boll stage of typeⅠand typeⅡ. The flowering stages are all annotated. Nine genes related to chlorophyll content were identified through relative expression analysis. Among them, genes such as GB_A05G0097, GB_A05G0093 and GB_D05G0109 play important roles in chlorophyll metabolism, photosynthesis and plant stress resistance. 【Conclusion】 There are significant differences in the chlorophyll content of sea-island cotton at different growth stages, and are significantly affected by the environment. A total of 52 loci related to the chlorophyll content of sea-island cotton were detected, and nine genes were found to be candidate genes for chlorophyll in sea-island cotton.
【Objective】 To identify and evaluate the drought resistance of alfalfa germplasm resources, screen out different drought-resistant alfalfa germplasm materials, and lay a foundation for further development of drought-resistant alfalfa resources creation and breeding utilization. 【Method】 In this study, A total of 111 alfalfa germplasm resources were used as experimental materials, and drought stress conditions were simulated using a 13% PEG-6000 solution. Two treatments were established: drought stress (13% PEG-6000) and a control (distilled water). Drought tolerance at germination stage were comprehensively evaluated by the comprehensive drought resistance coefficient (CDC value) and drought resistance coefficient (D value) using nine indicators, including germination potential, germination rate, germination index, vitality index, promptness index, root length, bud length, fresh weight and dry weight. Meanwhile, single drought tolerance coefficients, correlation analysis, principal component analysis and stepwise regression analysis were conducted to identify the key indicators influencing drought resistance during germination. 【Result】 Analysis of the single drought tolerance coefficients for the nine indicators showed that vitality index, fresh weight, and promptness index were key indicators for screening drought resistance at the germination stage. The single drought tolerance coefficients of the indicators had the highest correlation among germination index and promptness index, germination rate, vitality index, with coefficients of 0.9838, 0.9495 and 0.9338, respectively. Principal component analysis transformed the nine indicators into three principal components with a cumulative contribution of 87.287%. Drought resistance of alfalfa at germination stage was identified using two methods with CDC value and D value, and it was found that the evaluation results of the two methods were highly consistent; however, the D value method was more comprehensive, reliable, and accurate, as it used the weighting coefficients to reflect the degree of influence of each indicator to the overall drought resistance of the varieties. Based on the D value, the 111 alfalfa germplasm resources were clustered into five categories: ClassⅠ(strongest drought resistance, 1 accession), Class Ⅱ (strong drought resistance, 5 accessions), Class Ⅲ (moderate drought resistance, 55 accessions), Class Ⅳ (weak drought resistance, 37 accessions), and Class Ⅴ (drought-sensitive, 13 accessions). 【Conclusion】 The D value evaluation method was found to be the most reliable for assessing drought resistance in alfalfa during the germination stage; The study identified AG37 as the strongest drought resistance germplasm, along with five strong drought resistance accessions, including AG19, AG5, AG13 and other. Vitality index and promptness index were determined to be the most suitable indicators for evaluating drought resistance in alfalfa at the germination stage.
With the advancement of agricultural supply-side structural reforms and the growing demand for high-quality, safe, and eco-friendly agricultural products in China, cotton production now faces the challenge of coordinating multiple objectives, including yield enhancement, quality optimization, simplified and efficient management, and environmental sustainability. To address these challenges, this paper proposes the novel concept of multi-objective collaborative cultivation (hereafter termed “collaborative cultivation”). We systematically elaborate on the theoretical foundations underpinning this approach, including mechanisms of precision sowing for robust seedling establishment, synergistic water-fertilizer management under partial root-zone irrigation, population regulation through high-density planting with chemical regulation and pruning-free canopy shaping, physiological mechanisms of defoliation-ripening for synchronized boll maturation, and compensatory growth strategies ensuring yield stability under abiotic stress. Building on these theorical bases and international research insights, we identify four core technologies of collaborative cultivation: (i) precision sowing coupled with stress-resilient seedling establishment under adversity, (ii) high-density planting with chemical regulation for canopy shaping, (iii) variable-rate drip irrigation with water-fertilizer synergy management, and (iv) synchronized maturation control technology. Empirical evaluations demonstrate that the integrated application of these technologies optimizes resource utilization, enhances productivity, and ensures fiber quality consistency, while reducing labor inputs and chemical usage. Case studies from major cotton-producing regions validate that collaborative cultivation achieves synergistic outcomes in productivity, sustainability, and economic viability, aligning with green agricultural development goals. Future research priorities include optimizing multi-objective trade-offs, deciphering genotype-environment-management interactions, enhancing stress compensation mechanisms, and extending collaborative principles to multi-cropping systems. Through interdisciplinary innovation and technology integration, this framework offers a systemic solution for high-quality cotton industry development, demonstrating significant potential to drive the sector's green transformation and sustainable advancement.
【Objective】 To investigate the effects of different mulching methods and phosphorus (P) fertilizer application levels on the photosynthetic characteristics, yield, and water use efficiency of broad bean, so as to provide data support for the selection of broad bean planting modes and soil nutrient management practices in alpine regions. 【Method】 Used spring broad bean 'Qinghai No.13' as experimental material, a field experiment was conducted to investigate the effects of different mulching methods and P fertilizer application levels on soil hydrothermal conditions, the photosynthetic characteristics of broad bean, yield, and water use efficiency in the eastern of Qinghai Province from 2020 to 2023. For plot setup, the random block design was used, and three mulching methods were set up, i.e. double ridges and furrows mulch (DRM), and three ridges and furrows mulch (TRM), and no mulch (NMF), with three P fertilizer application levels (P0, no fertilizer; P1, 9.10 kg P·hm-2; P2, 18.2 kg P·hm-2). 【Result】 (1) Compared with NMF, DRM and TRM treatments increased the daily mean soil temperature within the 10 cm soil layer by 16.1% to 20.5% and 16.7% to 23.0%, respectively, and also increased soil water content and storage in the 0-2 m soil layer of broad bean growing season. (2) Compared with NMF, DRM and TRM treatments decreased the leaf transpiration rate, stomatal conductance, intercellular CO2 concentration, net photosynthesis rate and leaf area index during the flowering and podding periods, and deceased grain yield, aboveground biomass, and water use efficiency of broad bean too. The highest mean annual grain yield was 2 273 kg·hm-2 under NMF treatment, followed by 1 030 kg·hm-2 under TRM and 943 kg·hm-2 under DRM. (3) P fertilizer application enhanced the net photosynthetic rate, transpiration rate, intercellular CO2 concentration, stomatal conductance, and leaf area index in the flowering and podding periods of broad bean under NMF and DRM treatments, but the trends under TRM treatment were reversed. (4) The correlation analysis indicated that the grain yield, aboveground biomass, and water use efficiency were significantly positive correlated with the net photosynthetic rate, transpiration rate, intercellular CO2 concentration, stomatal conductance, and leaf area index, and were significantly negative correlated with the daily mean soil temperature of the growing seasons. 【Conclusion】 Ridge-furrow plastic film mulching treatments (DRM and TRM) inhibited the growth of broad bean in later growth stages, slowed down the growth rate of leaf area index, reduced photosynthesis, which resulted in the decreased grain yield, aboveground biomass, and water use efficiency. Under the conditions of this experiment, no mulch with flat planting combined with 18.2 kg P·hm-2 phosphorus fertilizer significantly enhanced photosynthetic area and photosynthesis, thus increase the grain yield and water use efficiency of broad bean, which could be used as an effective practice to increase broad bean productivity in alpine region.
【Objective】 This study aims to investigate the function of HpvATPase B protein, and to clarify the role of this protein in the action of Bacillus thuringiensis (Bt) crystal protein against the larvae of Holotrichia parallela. 【Method】 Based on transcriptome data of the H. parallela, the open reading frame (ORF) of HpvATPase B was identified and cloned. HpvATPase B was expressed in vitro using a prokaryotic expression system and detected by Western blot. The expression levels of HpvATPase B in different tissues of 2-day-old of 3rd instar larvae of H. parallela were determined using qRT-PCR. The binding characteristics of HpvATPase B protein to Bt Cry8Ea3 toxin were detected by Ligand blot and ELISA. Sf9 cells transfected with HpvATPase B were subjected to immunofluorescence and cell viability assays to evaluate the binding of HpvATPase B to Bt Cry8Ea3, and the changes in cell mortality after treatment with Cry8Ea3 were compared. 【Result】 The cloned HpvATPase B (GenBank accession number: MZ004965) is about 1 497 bp, encoding 498 amino acids with a predicted molecular weight of 55 kDa and an isoelectric point (pI) of 5.51. Three N-glycosylation sites (239N, 333N, 458N) and four O-glycosylation sites (4S, 8T, 23S, 28S) were predicted. HpvATPase B protein has the highest sequence identity (55%) with Trypoxylus dichotomus V-ATPase B (GenBank accession number: GJQ75664.1) and Oryctes borbonicus V-ATPase B (GenBank accession number: KRT83436.1). The recombinant plasmid pET30a-HpvATPase B was successfully constructed, yielding a 55 kDa protein with peak expression at 8 h post-induction. The HpvATPase B had the highest expression level in the Malpighian tubules. Ligand blot confirmed specific binding between HpvATPase B and Bt Cry8Ea3 but not Cry1Ab35. The affinity of HpvATPase B protein to Bt Cry8Ea3 and Cry1Ab35 was determined by ELISA. The binding ability to Bt Cry8Ea3 was strong, and the Kd was 7.20 nmol·L-1, but it did not bind to Cry1Ab35, and the affinity did not change with the concentration of Cry1Ab35. pFastBacTM HTA-HpvATPase B was constructed and Sf9 transgenic cells were successfully obtained. Immunofluorescence assay showed that HpvATPase B protein specifically bound to Cry8Ea3 toxin protein. Cell bioassay showed that when the concentration of Cry8Ea3 protein was 10 and 100 μg·mL-1, the average corrected mortality of transgenic cells was 25.92% and 75.53%, respectively, and the difference was significant (P<0.05), indicating that HpvATPase B was Bt Cry8Ea3 receptor protein. 【Conclusion】 HpvATPase B protein was identified as the receptor protein of Bt Cry8Ea3 through a series of in vitro binding assays, immunofluorescence analyses, and cytotoxicity evaluations. This protein plays a crucial role in mediating the toxic effects of Bt Cry8Ea3 on H. parallela larvae.
【Objective】 This study aimed to explore the effects of different residue return methods on nitrogen fractions, nitrogen mineralization and nitrogen-cycling genes in black soil of Northeast China, and to clear the soil nitrogen supply capacity and the change of soil nitrogen cycling gene community structure under long-term residue return. 【Method】 Based on the long-term experiment of black soil in Northeast China, the residue incorporated into soil (RI) and the residue covered on soil surface (RC) under monoculture maize were selected, with residue removed as control (CK). Nitrogen content in soil fractions were measured, soil nitrogen mineralization incubation was conducted by using leaching incubation at intervals, and fluorescence quantitative PCR (qPCR) was used to determine the copy number of nitrogen-cycling genes in soil. 【Result】 After 8-year experiment, compared with CK, RC significantly increased the content of particulate organic nitrogen (PON)(0.21 g·kg-1) and mineral-associated organic nitrogen (MAON) (0.27 g·kg-1) in surface (0-5 cm) soil, whereas RI only increased the content of MAON (0.13 g·kg-1) in soil (P<0.05). Residue return (RI and RC) markedly increased the microbial biomass nitrogen (MBN) in soil by 1.4-2.8 times (P<0.05), the RI had higher content of ammonium nitrogen (NH4+) and dissolved organic nitrogen (DON), while the RC had the lowest content of nitrate nitrogen (NO3-). In comparison with CK, residue return significantly enhanced soil nitrogen mineralization amount by 25.3%-83.2% (P<0.05), taking the descending order of RC>RI>CK. Residue return remarkably increased the potential of soil nitrogen mineralization (N0) and mineralization rate constant (k) (P<0.05) by using a first-order reaction kinetics model, both showing the highest values under RC, with N0 and k reached 199.8 mg·kg-1 and 0.31 mg·kg-1·d-1, respectively. Random forest analysis indicated that PON, MBN, and NO3- had greater impacts on N0. In addition, the abundance of nifH, AOB and nirS genes under residue return were enhanced and the abundance of AOA and nirK genes under residue return were declined in comparison with residue removed (P<0.05), which indicated that residue return could change the structure of soil nitrogen-cycling genes communities. Redundancy analysis (RDA) result showed that the changes of soil microbial community structure were affected by different nitrogen fractions under different residue return methods. 【Conclusion】 Long-term residue covered on soil surface had the highest organic nitrogen content and nitrogen mineralization potential in soil. It was beneficial to improve soil nitrogen pools and to ensure the supply of nitrogen required for plant growth, which provided greater possibility for reducing the application of chemical nitrogen fertilizer in cropland in black soil of Northeast China.
Green manuring is primarily used to support the production of main crops and to improve the farmlands’ ecology, thus lacks its own product unit. Studies have proved that it is an effective pathway to produce high-quality products. How to introduce such products into the market and serve more population is a challenge of the green manure industry. Over one decade of exploration and accumulation, we proposed the "Green Manure Plus" industry mechanism in 2018, and have continuously carried out scientific research and industrial practice around the new mechanism. The "Green Manure Plus" industry mechanism is the whole process based on the green manure production system, including using green manure technology to produce high-quality and healthy agricultural products for promoting the marketization of these products; the relevant products are called "Green Manure Plus" ones. The "Green Manure Plus" industry mechanism mainly includes developing the technology modes, building the production bases, materializing the products, and constructing the market systems. The "Green Manure Plus" products can be well done because green manuring can provide large amounts of clean and organic fertilizer sources, improve the soil quality effectively, and help the main crops achieve high productivity and quality with less fertilization. These characteristics of green manure form the theoretical basis for the development of “Green Manure Plus” products. The innovative mechanism has greatly expanded the green manure industry path, converting the disadvantage of unclear industry form into the advantage of the "Green Manure Plus" platform, which no longer being constrained by the product unit of green manure itself, and can play roles in different regions and agricultural systems. Over six years of development and practice, the diversified "Green Manure Plus" modes were constructed, including "Green Manure Plus" organic/clean rice, high-quality fruits, flour, tea, and vegetables, etc., providing the green manure’s path for the comprehensive rural revitalization for the new era. In future, the main goals of the "Green Manure Plus" industry are to strengthen the research and development of "Green Manure Plus" industry technology and product creation, to accelerate the construction of branding, marketization, and standardization, and to promote continuously the transformation of green mountains and lucid waters into invaluable assets by green manure’s practice.
