【Objective】To clone the target of rapamycin gene OsTOR in rice, and investigate its regulatory mechanism in root elongation, elucidate its biological function in rice development, and provide a molecular basis for improving rice traits and increasing its yield. 【Method】In this research, the japonica rice variety Dongjin was used as material for OsTOR expression pattern analysis via qRT- PCR. OsTOR was cloned by RT-PCR, and the overexpression vector 35S:OsTOR-GFP was constructed. The overexpression lines OsTOR-OX were generated by Agrobacterium-mediated rice genetic transformation to examine the subcellular localization of OsTOR. Rice seedlings were treated with TOR inhibitor AZD-8055, and the phenotype was observed. The root tips of inhibitor-treated and OsTOR-OX plants were cleared and the cell morphology in the meristematic zone was then visualized by CLSM. Transcriptome sequencing was performed on 7-day-after-germination (DAG) seedlings with or without AZD-8055 treatment. The expression of cell cycle related genes was further analyzed by qRT-PCR. 【Result】OsTOR was evolutionally closely related to barley and wheat TORs. It contains HEAT repeat domain, FAT, FRB, PIKKc kinase domain and FATc domain. OsTOR was localized in cytoplasm and cell membrane, and expressed in various tissues: leaves, leaf sheaths and roots of 7 DAG seedlings, as well as flag leaf blades, flag leaf sheaths, inflorescences, mature anthers, and unpollinated pistil of mature plant. AZD-8055 inhibited seedling growth and root elongation, accompanied by reduced cell proliferation in the root meristem. In contrast, OsTOR overexpression promoted root elongation. Transcriptome analysis revealed 225 genes were upregulated and 121 genes were downregulated upon AZD-8055 treatment. Among the upregulated genes, approximately 28% were associated with cell process, 18.6% with response to stimulus, and some others were involved in degradation. Downregulated genes were mainly involved in biosynthetic processes, protein metabolism, and cell cycle regulation. qRT-PCR results further confirmed that reduced OsTOR activity led to decreased expression of cell cycle-related genes. 【Conclusion】OsTOR was localized in cytoplasm and cell membrane, and was ubiquitously expressed in various tissues at different developmental stages of rice. Reduced OsTOR activity restrained seedling growth and root elongation, whereas OsTOR overexpression promoted root elongation. This effect was primarily attributed to altered expression of cell cycle-related genes, which subsequently affected cell proliferation in root meristem.
The soybean cropping system involves its distribution across the country, the lighting time, accumulated temperature and cropping system of the varieties, the rotation system, as well as the monocropping, intercropping and relay intercropping methods, serves as the foundation for soybean production, breeding, introduction, and technology innovation. Optimizing the soybean cropping system is of decisive significance for enhancing the comprehensive production capacity and benefits of soybeans in China. Since the founding of the People's Republic of China (PRC) 70 years ago, the area planted with soybeans in regions with one crop per year system has expanded, while the area in regions that have shifted from triple crops per two years system to double crops per year system has decreased. In areas that have transitioned from double crops per year and then to triple crops per year, the area planted with soybeans has remained stable with a slight increase. From a national perspective, the soybean cultivation region has expanded to the northern part of Northeast China, and the soybean cultivation region in the South and Southwest has remained stable with a slight increase. The Northwest region has performed a new high-yield area for soybeans. Historically, the division of soybean cultivation regions was based on the basic data, investigations and experiments of the planting system at that time. In the recent 30 years, there have been significant advancements in soybean production, breeding and cultivation techniques, especially in the changes of soybean cultivation areas. The division of ecological cultivation region is a fundamental task closely related to soybean cultivation, resource utilization, introduction and breeding for cultivars. Based on the review of the changes in soybean cultivation region in China since the PRC establishment, including the northward expansion and southward shift of cultivation region, the renewal and upgrading of varieties, the improvement of mechanization levels, the comprehensive progress of cultivation techniques, and the promotion of intercropping system, especially the emphasis on developing the soybean industry as a national policy in China since 2000, this review comprehensively analyzed the dynamic characteristics of the soybean cropping system and technical system in PRC and thus proposed suggestions for adjusting the ecological cultivation region divisions of soybeans. From which a new soybean ecological cultivation region system is proposed. The main results comprise the changes in soybean cropping regions and the advances in cropping system, the environmental cultivation regions and changes of soybeans, the ecology of modern soybeans in China, and discussion and prospect on ecological cultivation region of soybeans in China. Influenced by updates of soybean cultivars, advancements in cultivation and farming technology, and requirements on food security, the soybean cropping system has undergone significant changes. The new six ecological cultivation regions were suggested as Northeast Spring Planting Soybean Ecological Cultivation Region, Northwest Spring Planting Soybean Ecological Cultivation Region, Huang-Huai-Hai Summer Planting Soybean Ecological Cultivation Region, Changjiang Valleys Spring-Summer-Autumn Planting Soybean Ecological Cultivation Region, Southwest Plateau Spring-Summer Planting Soybean Ecological Cultivation Region, and South China All Season Planting Soybean Ecological Cultivation Region. This division and naming system is considered as consistent as that of the national crop cultivation system, and also pays attention to the connection with previous ecological cultivation region division systems in soybean.
【Objective】Thousand-grain weight (TGW), a key determinant of final wheat yield, is of great importance for genetic dissection. Precise identification of stable loci and key candidate genes controlling TGW provides theoretical foundations and genetic resources for marker-assisted breeding of high-TGW and high-yield wheat varieties. 【Method】A total of 291 wheat accessions from diverse origins were genotyped using a 100K SNP array. TGW phenotypic data collected over two consecutive years and their best linear unbiased predictions (BLUPs) were analyzed using a genome-wide association study (GWAS) based on a mixed linear model (MLM) incorporating both population structure (P) and kinship (K). Significant loci were further subjected to haplotype analysis. 【Result】TGW showed broad variation across years and BLUP values (mean: 38.24-38.82 g; coefficient of variation: 17.62%-19.93%). The correlation between years was 0.88 (P<0.01), and correlations with BLUP values reached 0.97 (P<0.01). Phenotypic data displayed normal distributions under different environments, meeting the basic requirements for GWAS. A total of 19 SNPs significantly associated with TGW were detected on chromosomes 3B, 5A, and 7A, explaining 6.85%-9.68% of the phenotypic variation; 16 of them were repeatedly detected across multiple environments, indicating stability. Haplotype analysis at locus 7A_145980808 revealed four haplotypes (Hap1-Hap4), of which Hap4 was associated with high TGW (P<0.01) and Hap2 with low TGW (P<0.01). The frequencies of Hap1-Hap4 were 72.36%, 14.55%, 8.73%, and 4.36%, respectively. Domestic accessions were enriched for Hap3 (95.83%) and Hap4 (83.33%), with Hap4 predominantly distributed in the Northwestern winter wheat region, especially in germplasm from Gansu. Candidate gene mining within 3.6 Mb regions flanking significant loci on chromosomes 3B, 5A, and 7A identified 95 genes, among which four were highlighted based on gene annotation and expression profiles. 【Conclusion】GWAS identified 16 stable SNP loci significantly associated with TGW, four distinct haplotypes, and four key candidate genes. These genes are mainly involved in carbohydrate synthesis and transport, cell wall polysaccharide assembly, protein homeostasis, and transcriptional regulation of starch biosynthesis, providing valuable targets for molecular breeding of high-yield wheat.
【Objective】Zn (Zinc) deficiency triggers ‘hidden hunger’. Enhancing Zn concentration in wheat grains and Zn fertilizer use efficiency through biofortification can effectively increase dietary Zn intake, thereby improving human Zn nutritional status. 【Method】The study subjects were two distinctive colored-grain wheat varieties: ‘Taihei 5’ (purple-grained) and ‘Tailan 8’ (blue-grained). A two-year field experiment was conducted from 2022-2024 in Taigu District, Jinzhong City, Shanxi Province. Foliar Zn application was performed at 3-5 days after the flowering of colored-grain wheat (Over 50% of spikes in the wheat field had lemma and palea separation at middle-upper florets while anthers were dehiscing). Five Zn concentration treatments were applied: Zn0 (deionized water), Zn1 (Zn concentration: 440 mg·L-1), Zn2 (Zn concentration: 587 mg·L-1), Zn3 (Zn concentration: 733 mg·L-1), Zn4 (Zn concentration: 880 mg·L-1). Through analysis of grain yield and Zn concentrations in grains, leaves, and stems across multiple post-anthesis periods for both colored-grain wheat types, Zn concentration variation dynamics, Zn accumulation and partitioning characteristics, Zn utilization efficiency, grain Zn biofortification index and grain Zn harvest indices were quantitatively analyzed to evaluate their Zn biofortification efficacy. 【Result】Foliar Zn application significantly increased Zn concentrations in all organs and grain yield of colored-grain wheat, The Zn3 treatment produced the highest grain Zn concentration (21.79-67.90 mg·kg-1) and peak grain yield (4 937.36-5 097.27 kg·hm-2). Grain Zn accumulation reached its optimum (251.30-301.54 g·hm-2) under the Zn3 treatment, while Zn concentrations and accumulation in leaves and stems increased linearly with rising application concentrations. With increasing Zn application concentrations, the grain Zn accumulation proportion showed a declining trend (10%-18%), while the leaf Zn accumulation proportion rose to 66%, and stem Zn accumulation remained at 23%-30%. Furthermore efficient synergy in Zn utilization efficiency across all organs of colored-grain wheat was achieved under Zn3 treatment (5.68%-7.70%). With increasing Zn application concentrations, the grain Zn biofortification index and Zn harvest index declined. Compared with Zn1, other Zn treatments reduced the grain Zn biofortification index by 12.50%-47.02%, while relative to the control (Zn0), all Zn treatments decreased the Zn harvest index by 23.66%-60.44%. ‘Taihei 5’ outperformed ‘Tailan 8’ in grain Zn concentration, accumulation, utilization efficiency, and biofortification performance. Possibly influenced by precipitation, both types of colored-grain wheat performed better in the second growing season 【Conclusion】Post-anthesis foliar Zn application effectively regulated Zn accumulation and partitioning in colored-grain wheat. The combination of purple-grained wheat varieties and foliar Zn application at 733 mg·L-1 achieved the optimal balance between grain Zn concentration and Zn utilization efficiency in colored-grain wheat systems.
【Objective】This study aimed to investigate the effect of potassium (K) on the waterlogging tolerance of rapeseed (Brassica napus L.) and elucidate the physiological regulatory mechanisms involving K in the plant's response to waterlogging stress, to provide a theoretical basis for effective waterlogging management in rapeseed production. 【Method】A sand culture pot experiment was conducted with two water treatments: well-watered (CK) and waterlogging (WL), and two potassium levels: 1.0 mmol K2SO4·L-1 (HK) and 0.1 mmol K2SO4·L-1 (LK). Seven-day waterlogging stress was imposed at the seedling stage. Differences in growth, photosynthetic characteristics, antioxidant enzyme activities, and endogenous hormone levels under different K levels were compared. 【Result】Rapeseed growth was significantly affected by waterlogging and K level. Biomass, root-shoot ratio, and net photosynthetic rate consistently exhibited the hierarchical pattern: HK_CK>HK_WL>LK_CK>LK_WL. Waterlogging elevated superoxide dismutase (SOD) and catalase (CAT) activity in leaves, while the activities of both enzymes were suppressed in LK treatments (LK_CK and LK_WL) compared to HK treatments (HK_CK and HK_WL). Consequently, the MDA content was significantly higher in the LK treatments than in the HK treatment. Waterlogging and K deficiency profoundly altered the endogenous hormone profiles in rapeseed. Leaf abscisic acid (ABA) cotent progressively increased across treatments: HK_CK<HK_WL<LK_CK<LK_WL. Both waterlogging and potassium deficiency significantly increased the leaf jasmonic acid (JA) content after 7 d of waterlogging stress, peaking at LK_WL treatment. Waterlogging and K deficiency induced salicylic acid (SA) accumulation, with the highest SA content observed in LK_WL treatment. During the recovery stage, both waterlogging and potassium deficiency induced the decrease of indole-3-acetic acid (IAA) content in root and leaf, with the most pronounced depletion occurring in LK treatments (LK_CK and LK_WL). 【Conclusion】Waterlogging stress inhibited rapeseed growth and severely restricted root development. Root growth and K+ uptake were significantly promoted, and leaf photosynthetic capacity as well as SOD and CAT activities were enhanced by elevated K levels, thereby improving waterlogging tolerance. Waterlogging stress triggered the accumulation of ABA, JA, and SA in leaves. The stress responses induced by ABA and JA accumulation were significantly alleviated by improved K levels and promoted the accumulation of IAA in roots and leaves after stress removal, facilitating the recovery growth of rapeseed.
【Objective】Pepper mild mottle virus (PMMoV) belongs to the species Tobamovirus capsicai in the genus Tobamovirus (family Virgaviridae), has emerged as an important pathogen, significantly impacting pepper yield and quality. The objectives of this study are to investigate its phylogeographic history and evolutionary dynamics, and to lay the foundation for accurate monitoring and scientific prevention and control. 【Method】A specific primer pair flanking the PMMoV coat protein (CP) gene was designed. The CP gene sequences of 28 randomly selected PMMoV isolates from Fujian Province were subsequently amplified and cloned. In addition to the newly obtained sequences, all publicly available CP sequences from GenBank with known collection timestamps and geographical origins were assembled into a final dataset of 255 sequences. After confirming a sufficient temporal signal via a date-randomized test (DRT), a structured coalescent-based Bayesian phylodynamic framework (MultiTypeTree) was employed to reconstruct the evolutionary history and spatial dissemination of the virus. 【Result】A target fragment with the expected size was obtained from all 28 PMMoV-positive samples selected in this study. Their CP sequences share >98% nucleotide identity with known PMMoV isolates. The DRT showed no overlap in the 95% confidence intervals of substitution rates between the real and randomized datasets, confirming a reliable temporal signal for Bayesian molecular dating. Phylogenetic analysis estimated a mean substitution rate of 9.24×10-4 substitutions/site/year (95% CI: 6.20×10-4-1.01×10-3 substitutions/site/year) for the PMMoV CP, which is comparable to rates observed in animal RNA viruses, indicating its rapid evolutionary dynamics. The time to the most recent common ancestor (tMRCA) was dated to 1941 (95% CI: 1921-1957). The root of the maximum clade credibility (MCC) tree was placed in Europe, identifying this region as the most probable origin of contemporary global PMMoV isolates. Temporal migration analysis revealed multiple dispersal routes from Europe to other regions, underscoring its role as a central hub in the virus’s global dissemination. In addition to cross-regional transmission, frequent local spread of PMMoV was observed within regions. Bayesian skyline plot (BSP) analysis further revealed distinct historical population dynamics: the South American population underwent a significant expansion before stabilizing, whereas those in most other regions remained relatively stable over the long term. 【Conclusion】Europe served as the most likely source and a critical dissemination hub for the global spread of PMMoV. This study provides a foundation for understanding the molecular epidemiology of PMMoV and informs the development of future disease management strategies.
【Objective】Gram-negative binding proteins (GNBPs), also known as β-1,3-glucan recognition proteins, represent a class of crucial pattern recognition receptors (PRRs) in insects and play pivotal roles in the innate immune response. This study aimed to systematically identify members of the PxGNBP gene family in the diamondback moth (Plutella xylostella), analyze their structural characteristics and expression patterns, as well as screen and validate key target genes. The findings are expected to reveal the innate immune mechanisms and evolutionary adaptations of P. xylostella in response to pathogenic infection, thereby providing theoretical foundations and potential targets for the development of novel biological control. 【Method】Based on the whole-genome data of P. xylostella, members of the PxGNBP gene family were identified. Bioinformatic approaches were comprehensively employed to analyze their structural characteristics and evolutionary relationships, and AlphaFold3 was used to predict their three-dimensional structures. In addition, combined with public transcriptome data and quantitative real-time polymerase chain reaction (RT-qPCR) technology, the expression patterns of these family members in different tissues and post-infection with Beauveria bassiana and Metarhizium anisopliae were detected. Recombinant M. anisopliae strains carrying pSilent-PxGNBP3 were constructed. The expression levels of PxGNBP3 and downstream antimicrobial peptide genes post-infection were determined via RT-qPCR, and the pathogenicity of different strains against P. xylostella was evaluated using bioassays. 【Result】A total of 10 PxGNBP members were identified in P. xylostella. Among them, PxβGRP4 is located on chromosome 22 and belongs to the glucanase subfamily, while the remaining 9 members are located on chromosome 29 and belong to the PRR subfamily. Phylogenetic and chromosome location analyses suggested the occurrence of tandem duplication events within this gene family. Conserved motif analysis indicated that the N-terminal domain of PxGNBP exhibited lower conservation compared to the C-terminal domain. Except for PxβGRP4, the key catalytic sites of glucanase in other members were mutated. Three-dimensional structure predictions revealed that all members, except PxβGRP4 and PxβGRP3, possessed the typical GNBP protein structure; the C-terminus of PxβGRP3 contained a structural fragment that was similar but not identical to Carbohydrate-binding module 39 (CBM39). Expression profile analysis demonstrated that most members exhibited a time-series expression pattern of first increasing and then decreasing after infection with the two fungi. RNA interference (RNAi) assays showed that the recombinant M. anisopliae strains could effectively suppress the expression of PxGNBP3, leading to a significant reduction in antimicrobial peptide expression levels and a decrease in host survival rate. Moreover, the virulence of recombinant strains was significantly higher than that of the wild-type strain and enhanced with increasing concentration. 【Conclusion】Ten members of the GNBP gene family were identified in P. xylostella, with PxβGRP3 and PxGNBP3-2 showing structural specificity. This gene family exhibited a time-series regulatory expression pattern in response to fungal infection. In vivo functional validation of PxGNBP3 via RNAi was successfully achieved using the constructed recombinant M. anisopliae strains. The results provide important insights for elucidating the innate immune mechanisms of P. xylostella and developing novel targets for biological control.
【Objective】In order to provide the theoretical support for soil structure improvement and phosphorus activation of Shajiang black soil, the regulatory effects of wheat and maize straw return on aggregate size distribution and phosphorus fractions of soil aggregates were investigated. 【Method】This study was based on a long-term straw return experiment (since 2008) conducted in Mengcheng County, Anhui Province. The experimental design included four treatments: conventional fertilization (F), conventional fertilization plus wheat straw return (FWS), conventional fertilization plus maize straw return (FMS), and conventional fertilization plus wheat and maize straw return (FWMS). Soil samples of cultivated layers (0-20 cm) were collected at wheat maturity stage in 2023 to determine the composition of soil aggregates and the content of phosphorus fractions in different particle-size aggregates. The effects of wheat and maize straw return on the distribution of phosphorus fractions in soil aggregates, the phosphorus activation rates of different size aggregates and their contribution rates to soil available phosphorus were analyzed. 【Result】Compared with the F treatment, the proportions of >2 mm aggregates in Shajiang black soil under FWS, FMS and FWMS treatments were significantly increased by 35.9%, 30.6% and 39.1%, respectively, while the proportions of 0.25-2 mm aggregates and microaggregates (0.053-0.25 mm) were significantly decreased. Wheat and maize straw incorporation significantly increased the mean weight diameter (MWD) of water-stable aggregates and decreased the percentage of aggregate disruption (PAD). Under the condition of straw return, the contents of soil total phosphorus and available phosphorus were significantly increased by 6.5%-26.0% and 21.1%-37.6%, respectively. Wheat and maize straw return could significantly elevate the contents of labile phosphorus fraction NaHCO3-Pi (17.1%-51.3%) and moderate labile phosphorus fraction NaOH-Po (19.5%-46.2%) in Shajiang black soil. Compared with the F treatment, the soil available phosphorus contents and phosphorus activation rates of 0.25-2 mm aggregates under the straw return treatments were significantly increased by 39.3%-63.9% and 37.5%-51.7%, respectively. The relative contribution rates of >2 mm aggregates to soil available phosphorus under FWS, FMS and FWMS treatments were significantly increased by 19.0%, 17.3% and 22.3%, respectively, compared with the F treatment. However, straw incorporation significantly reduced the relative contribution rates of microaggregates (0.053-0.25 mm) and silt and clay particles (<0.053 mm) to soil available phosphorus. The contents of labile phosphorus (H2O-P, NaHCO3-Po) and moderate labile phosphorus (NaOH-Po) in 0.25-2 mm aggregates were increased under straw return. 【Conclusion】Wheat and maize straw return was an effective measure to improve the composition and stability of soil aggregates in Shajiang black soil, and could enhance the soil phosphorus supply capacity.
【Background】Improving water use efficiency is beneficial for the sustainable production of wheat. Both ridge and furrow planting and soil moisture-based supplemental irrigation techniques can significantly enhance crop water use efficiency. However, whether the combination of these two approaches can achieve effective water-saving outcomes and further improve the water use efficiency of wheat remains unclear. 【Objective】This study aimed to explore the effects of ridge-furrow planting combined with soil moisture measurement and supplementary irrigation on the population, yield and water use efficiency of wheat. 【Method】In this study, a two-year field experiment was conducted. The winter wheat variety Xinong 20 was selected, and three planting methods of furrow sowing (P1), ridge sowing (P2) and flat planting (P3) were used. Three irrigation treatments were set up, including supplementary irrigation of soil moisture content in the 0-40 cm soil layer to field water holding capacity (S40), supplementary irrigation of soil moisture content in the 0-60 cm soil layer to field water holding capacity (S60), and traditional flood irrigation as the control irrigation (SCK). By measuring the soil moisture content, the dynamics of tillers of winter wheat, dry matter accumulation, yield and its constituent factors, and calculating the total water consumption of farmland, precipitation use efficiency, irrigation water use efficiency, total water consumption use efficiency, border row index and economic benefits, the effects of ridge-furrow planting and soil moisture measurement-based supplementary irrigation techniques on the growth and development, yield, water use efficiency and economic benefits of winter wheat were explored. 【Result】The furrow sowing combined with soil moisture measurement and supplementary irrigation at 60 cm depth (P1S60) maintained similar soil water content, tillers number, and dry matter accumulation as the flat planting with traditional flood irrigation (P3SCK). By leveraging the marginal effect, furrow sowing increased spike number and grains per spike of border-row winter wheat. For ensuring stable wheat yield, P1S60 saved 34.5% of irrigation water and reduced total farmland water consumption by 10.8%. It also boosted irrigation water use efficiency (IWUE) by 79.5% and water use efficiency (WUE) by 14.7% (two-year average). Compared with P3SCK, P1S60 raised total income by 3.2%, indicating high economic viability. 【Conclusion】Considering the utilization efficiency of water resources, yield and income potential, P1S60 was a planting method with high potential in Guanzhong irrigation area.
【Objective】In light of the shortage of water resources and the lower fertility and poor quality of soils in Xinjiang, this study explored the effects of varying irrigation volumes and ratios of organic to inorganic fertilizer application under aerated drip irrigation on the soil quality, cotton growth, yield, and water use efficiency of cotton fields. The objective was to provide a theoretical basis for determining an irrigation and fertilization model for cotton in Xinjiang that was water-saving, highly efficient, and sustainable. 【Method】Field experiments were conducted in the 146th Regiment area of the Xinjiang Production and Construction Corps in 2023 and 2024. Under aerated drip irrigation, two irrigation volumes (W1: 80%ETC and W2: 100%ETC, where ETC represents the crop evapotranspiration) and five ratios of organic to inorganic fertilizer application (OF1: 100% chemical fertilizer, OF2: 75% chemical fertilizer + 25% organic fertilizer, OF3: 50% chemical fertilizer + 50% organic fertilizer, OF4: 25% chemical fertilizer + 75% organic fertilizer, OF5: 100% organic fertilizer) were set up to study their impacts on the physical and chemical properties of soil quality, cotton growth including leaf area index (LAI), dry matter accumulation, yield, and water use efficiency (WUE). 【Result】The Soil Quality Index (SQI) increased with the rising proportion of organic fertilizer, showing an average increase of 9.9%-28.8% in the combined application of organic and inorganic fertilizers over the two years compared with the application of chemical fertilizer alone. Under deficit irrigation, soil moisture content, LAI, dry matter accumulation, and yield significantly decreased, while Water Use Efficiency (WUE) significantly increased. Under the two irrigation levels (W1 and W2), soil moisture content, cotton LAI, and dry matter accumulation first increased and then decreased as the proportion of organic fertilizer increased. Under W1, these indicators reached their maxima with the W1OF3 treatment, whereas under W2, their maxima were observed with the W2OF2 treatment. Compared with chemical fertilizer alone (OF1), the combined application of organic and inorganic fertilizers increased soil moisture content, LAI, and dry matter accumulation by 0.4%-5.2%, 4.1%-19.8%, and 3.7%-18.8% over two years, respectively. Over two years, the maximum seed cotton yield was observed under W2OF2 treatment, with an average yield of 6 739.99 kg·hm-2, but the highest WUE was achieved under the W1OF3 treatment, with an average value of 1.42 kg·m-3. The SQI, seed cotton yield, and WUE under different treatments were evaluated using the membership function method, TOPSIS method, and grey relational analysis, respectively. A comprehensive evaluation was carried out using an integrated differential combination evaluation model, determining the optimum treatment as W1OF3. 【Conclusion】Considering the priority of water-saving, while ensuring yield, and aiming to improve Water Use Efficiency (WUE) and soil quality, it was recommended that under aerated drip irrigation, applying 80% ETC for irrigation water volume and a combined application of 50% organic fertilizer and 50% chemical fertilizer, for serving as the optimal management measure for water-saving and efficient production in cotton fields in Xinjiang.
【Objective】 This study aims to obtain interspecific hybrid plants and analyze the botanical characteristics of hybrids between Zhangqiudawutong welsh onions (A. fistulosum) and Qingganjiu (A. przewalskianum Regel), so as to provide a basis for the efficient utilization of wild resources in the Allium genus. 【Method】 Taking Zhangqiudawutong welsh onion and Qingganjiu as experimental materials, flowering induction and reciprocal cross were conducted on both parents. Ovary cultivation technique was applied to obtain F1 hybrid plants. The authenticity of hybrid F1 was identified by means of chloroplast genome sequencing, flow cytometry detection, karyotype analysis, ITS analysis, and phenotypic characteristics. The botanical characteristics of hybrids were observed at the seedling stage, vegetative growth stage, and bolting-flowering stage. Their fertility was identified through observation and self-pollination. The color, texture and taste of the product were assessed via sensory assessment to determine its potential as an emerging vegetable. Differential metabolites between hybrid varieties and their parental lines were analyzed using widely-targeted metabolomics. 【Result】There was a significant difference in the seedling rates between reciprocal crosses of Zhangqiudawutong welsh onion and Qingganjiu. Ovaries from the cross of Zhangqiudawutong welsh onions (♀) × Qingganjiu (♂) expanded normally, whereas those from the reciprocal cross failed to expand and instead wilted and dried out. Ten days after pollination, natural ovaries ceased swelling, gradually turned grayish-white, became soft-textured, and eventually withered. Through ovary culture, 36 F1 hybrid plants were obtained, with a germination rate of 46.25% and a seedling rate of 22.50%. The chloroplast genome sequence of hybrid F1-16 was consistent with that of the maternal parent (Zhangqiudawutong welsh onion), indicating maternal inheritance of the cytoplasm. The peak of chromosome fluorescence intensity was 32.90×105, which was between the two parents. The karyotype formula of chromosomes was 2n=2x=16=16m (1SAT), belonging to type 1A. The ITS sequence haplotypes included two types, which were identical to those of the two parents, respectively. The MAPI_1 molecular marker was developed, and the detection results showed that Zhangqiudawutong welsh onions (♀) had a single 124 bp band, while Qingganjiu (♂) had a single 289 bp band. Both bands were amplified in all 36 F1 hybrid individuals. F1 hybrid plants showed strong heterosis, with an average of 17.50 tillers per plant. Notably, their biomass yield reached 387.52 g per tiller group, which was significantly higher than that of their parents. All F1 individuals were pollen-sterile, exhibiting male sterility, and propagated vegetatively via tillering and aerial bulbils instead. A total of 1 208 metabolites were detected in both parents and hybrid F1-16, and 153 metabolites showed significant differences between F1-16 and its parents. Among these, 97 metabolites were upregulated and 56 metabolites were downregulated in F1-16 compared to the parents. Additionally, F1-16 produced a novel metabolite, Phloretin-2'-O-glucoside (Phloreizin), which has extremely high medicinal and health value. 【Conclusion】Interspecific hybrid F1 between Zhangqiudawutong and Qingganjiu was successfully obtained using ovary culture technology. F1 exhibited obvious heterosis and male sterility. A method for developing molecular markers to identify distant hybrid species was designed and validated.
