【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】 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.

【Objective】 Plant height is a trait that plays an important role in the increase of foxtail millet yield. The dynamic changes of foxtail millet plant height at different growth stages were studied, and the QTL loci and effects controlling plant height were identified to provide a theoretical basis for plant type breeding of foxtail millet. 【Method】 In this study, a recombinant inbred line population YRRIL containing 215 lines were used as the research object, and the YRRIL population was planted in two environments, Yulin, Shaanxi and Mizhi, Shaanxi, in May 2023, respectively. The phenotypic values of plant height trait of each family were measured at five stages: seedling, elongation, booting, tasseling, and ripening period, respectively. Combined with the genetic linkage map of the YRRIL population, genetic analysis and dynamic QTL mapping of plant height trait at different growth stages of millet were carried out, and the unconditional QTL and conditional QTL controlling plant height of millet were identified. On this basis, candidate gene prediction for important QTL was carried out using Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis methods. 【Result】 In the entire growth period of the millet plant height growth trend was the “S” type curve, from the elongation stage to the booting stage, the growth rate of plant height was faster, which was the key stage of plant height development. In the two environments, plant height of each family line of the population showed continuous distribution at different periods. A total of 86 QTL related to plant height were detected at five periods in the two environments, which were distributed on all 9 chromosomes of the foxtail millet genome. It contained 48 unconditional QTL and 38 conditional QTL, and the phenotypic contribution rate of unconditional QTL was 1.13%-17.49%, of which 6 could be detected repeatedly at two growth periods, and the rest were detected only at one growth period. The phenotypic contribution rate of conditional QTL was 1.97%-14.69%, of which one could be detected repeatedly at two growth stages, and the rest were detected only at one growth stage. No QTL that can be detected in three or more periods were present in either unconditional QTL analysis or conditional QTL analysis. A total of 12 major QTL were detected by unconditional QTL and conditional QTL analysis in two environments, of which 6 QTL were newly identified as primary loci in this study. Based on the prediction and analysis of genes within the main effect QTL interval combined with functional annotation of homologous genes screened out 14 candidate genes that might be related to foxtail millet plant height, among which Seita.1G242300.1, Seita.6G110200.1, and Seita.7G143300.1 were all able to directly regulate plant height development. 【Conclusion】 In the two environments, a large number of QTL were detected to be involved in the phenotypic regulation of plant height trait during the whole growth and development of foxtail millet, with 79 (91.86%) played a role in one period and 7 (8.14%) played a role in two periods and there were no QTL detected in three or more periods, including 12 major QTL. The QTL detected by unconditional and conditional analysis methods accounted for 55.81% and 44.19%, respectively, and 16 (18.60%) were both unconditional and conditional QTL. The QTL effects controlling plant height development at different stages varied, with smaller effect in the seedling stage and generally larger effects from the elongation to the tasseling stage.

【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】 The Huang-Huai-Hai Plain is a typical annual rotation area of winter wheat and summer maize in China, and the effect of pre-season tillage on the yield of summer maize in this area was studied, so as to provide a theoretical basis for optimizing the tillage mode under the wheat-maize double cropping system to improve the high and stable yield of summer maize. 【Method】 Based on the 6-year long-term positioning experiment, three pre-sowing tillage modes of winter wheat were set up, including Deep tillage (DT), No-tillage (NT), and Rotation tillage (RT) with deep tillage for one year and two years, to explore the tillage mode with the greatest potential for increasing summer maize yield. 【Result】 RT and DT treatments significantly increased the soil water storage of 0-40 cm soil in tillage disturbance during the tillage period of summer maize at the grain filling stage, which was 4.89% to 11.02% (2022) and 4.43% to 6.06% (2023) higher than that under DT treatment, and 8.16% to 16.69% (2022) and 6.78% to 17.23% (2023) higher than that under NT treatments, respectively. RT treatment could maintain a high leaf area index at the maize grain filling stage, and the leaf area index under RT treatment increased by 1.41% to 14.28% (2022) and 9.03% to 14.46% (2023) compared with DT treatment before and during the grain filling stage, respectively and increased by 14.80% to 27.56% (2022) and 21.25% to 29.39% (2023) compared with NT treatment, respectively. Compared with DT and NT treatments, the contribution rate of dry matter transfer after anthesis to grain under RT treatment increased by 3.77%, 40.36% (2022) and 7.26%, 19.91% (2023), respectively. The results of logistic equation simulation showed that the parameters of the 3 grain filling stages were roughly in the order of rapid growth stage>gradual growth stage>slow growth stage, and the three grain positions showed the lower grain>the middle grain>the upper grain, and the changes of the parameters in the 3 treatments showed RT>DT>NT, in which the RT treatment reached the maximum grouting rate in advance, and the average grouting rate was the highest, thereby increasing the theoretical maximum 100-grain weight. In 2022 and 2023, the yield under RT was significantly increased by 8.92%, 14.15%, 6.25% and 19.45% compared with DT and NT treatments, respectively, and in 2022 and 2023, the 100-grain weight RT and DT treatments were significantly increased by 2.71%, 6.03%, 9.02% and 12.56% compared with NT treatments, respectively. According to the structural equation model of yield formation, the direct effect and indirect effect of 0-40 cm soil water storage on yield were 0.420 and 0.551, respectively. 0-40 cm soil water storage not only directly promoted yield formation, but also affected yield through aboveground biomass and average grain filling rate. 【Conclusion】 In conclusion, soil water storage was an important driving factor for increasing yield, and RT could increase soil water storage at summer maize filling stage, thereby increasing leaf area index with higher activity, delaying leaf senescence time, increasing dry matter accumulation, optimizing grain filling characteristics, promoting the increase of dry matter to grain filling rate, and ultimately increasing summer maize yield.

【Objective】 This study aimed to construct a planting suitability evaluation method for compatible with geographical indication agricultural products, and to make up for the deficiencies in traditional crop planting suitability evaluation method due to the unique growing environment of geographical indication agricultural products, so as to provide important scientific references for optimizing the planting of geographical indication agricultural products. 【Method】 Taking Shanggao County of Jiangxi Province as the study area, MaxEnt model was used to predict the suitability range and optimal value of each index factor, and niche-fitness model was used to calculate the ecological niche suitability value of each evaluation unit. A comprehensive model of suitability index was established based on ecological niche theory by combining MaxEnt model and niche-fitness model, which was used to analyze the suitability of cultivation of purple-skinned garlic, a geographical indication agricultural product of the study area, from the four aspects of climate, soil, site conditions and cultivation conditions.【Result】 The suitable range of each index predicted by MaxEnt model was similar to the current data of purple-skinned garlic planting in Shanggao County, which indicated that the prediction results had high credibility. In addition, the natural breakpoint method was applied to classify the suitability level of each evaluation unit, including four levels: highly suitable, more suitable, barely suitable, and unsuitable areas. Among them, the highly suitable area was 627.03 hm², centrally located in Taxia Township, Mengshan Township, and Nangang Township; the more suitable area was 1 434.93 hm², mainly located in Sixi Township, Moshan Township, and Xujiadu Township; the barely suitable area was 1 908.86 hm², mainly located in the Yeshi Township and the Xinjiebu Township; the unsuitable area was 1 381.43 hm², mainly located in Luzhou Township, Zhendu Township, Aoshan Township, and Xinjiebu Township.【Conclusion】 Tianshan and Jiangnan villages were recommended as seed planting villages, and Magang and Meisha villages were recommended as extension planting villages. The results predicted by the MaxEnt model reduced the subjectivity of the suitability range and optimal value of each indicator in the niche-fitness model, and improved the credibility of the prediction results. The ecological niche model constructed by combining the niche-fitness model and MaxEnt model effectively predicted the suitable planting area of purple-skinned garlic, a geographical indication agricultural product of Shanggao County, and provided a new idea for the study of planting suitability evaluation of geographical indication agricultural products in similar regions.

【Objective】 The fatty acid compound 2E, 4E-decadienoic acid (DDA) was obtained from coculture of Bacillus subtilis Tpb55 and Trichoderma asperellum HG1, which has a specific inhibitory effect on Phytophthora. The objective of this study is to evaluate the effects of DDA on tobacco black shank (caused by P. nicotianae) and on the microbial community of tobacco rhizosphere soil, and to provide a basis for the application of such natural products in the prevention and control of plant Phytophthora disease. 【Method】 To evaluate the control efficacy of DDA against tobacco black shank, a pot experiment was performed, and the DNA copies of P. nicotianae in tobacco rhizosphere soil were detected by real-time fluorescence quantitative PCR technique. The bacterial, fungal and oomycetal communities in tobacco rhizosphere soil were analyzed through Illumina Hiseq high-throughput sequencing, and the correlation between soil nutrient factors and microbial community structure was assayed based on redundancy analysis and Mantel test. 【Result】 Compared with the control treatment with 0.5% DMSO, the treatment with 1.25 g·L^-1 DDA for root irrigation showed 77.06% and 84.35% decrease for black shank disease index and P. nicotianae DNA copy number, respectively. DDA treatment also significantly increased the soil pH from 6.72 to 6.82, improved the soil conductivity by 102.11%, and decreased the soil organic matter by 13.05%. DDA treatment had no significant effect on the diversity and richness of fungi and bacteria in tobacco rhizosphere soil. However, the OTU level, Shannon index, Chao1 index, and ACE index of oomycetes significantly increased, while the Simpson index significantly decreased. The PCoA results showed that DDA treatment significantly affected the structure of tobacco rhizosphere oomycete community (r=0.667, P=0.028), but had no significant effect on fungi (r=0.259, P=0.305) and bacteria (r=0.593, P=0.098). The relative abundance of gram-positive bacterial genera such as Phycicoccus and Terrabacter significantly increased in DDA treatment, while the abundance of gram-negative bacterial genera including Devosia, Bordetella and Pseudoxanthomonas significantly decreased. Some beneficial fungi such as Aspergillus, Albifimbria, Arcopilus were enriched by DDA. For oomycetes, the relative abundance of Phytophthora was significantly decreased, but that of Globisporangium increased. The Mantel test results indicated that the changes in soil physicochemical properties caused by the application of DDA had no significant impact on the rhizosphere microbial community. 【Conclusion】2E, 4E-decadienoic acid (DDA), as a novel natural fatty acid compound, can effectively prevent and control tobacco black shank, reduce the pathogen DNA copy number in tobacco rhizosphere soil, and specifically regulate the structure of oomycete community. It has the application potential in the prevention and control of crop oomycete diseases.

Sex pheromones are species-specific, easy-to-use, and environmental-friendly, using sex pheromones to monitor and control agricultural and forestry pests has promising prospects to meet the demands for sustainable agriculture in China. Elucidations of the moth sex pheromone biosynthetic pathways and key catalytic enzymes are of vital importance because they can serve as a theoretical basis for producing moth sex pheromones with synthetic biology strategies. According to the chemical structures and the biosynthetic pathways, moth sex pheromones are divided into four categories, namely Type-I, Type-II, Type-III, and Type-0, and the majority belongs to the former two categories, accounting for approximately 75% and 15%, respectively, of the known moth sex pheromones. Among the Type-II epoxidized sex pheromones, about 54% is monoepoxide. In terms of the biosynthetic site, Type-I sex pheromones are synthesized in the female sex pheromone glands, while Type-II hydrocarbon sex pheromones are produced in the oenocytes and only the final epoxidation occurs in the sex pheromone glands. In regards to the biosynthetic pathways and catalytic enzymes, Type-I sex pheromones are de novo synthesized from the fatty acid metabolic pathway and the involved enzymes that have been reported are fatty acyl desaturase, fatty acyl-CoA reductase, alcohol oxidase and acetyltransferase, and Type-II polyunsaturated hydrocarbons are derived from dietary linoleic and linolenic fatty acids, the identified involved enzymes include terminal desaturase, lipid transport protein lipophorin and P450 epoxidase. In addition, the current research status of the biological production of moth sex pheromones in plant and yeast cell factories is summarized. To further develop bio-factories for moth sex pheromone production with synthetic biology strategies, the remaining problems and research prospects faced in moth sex pheromone biosynthesis and bio-production are proposed as well.

【Objective】 This study aimed to explore the optimum tillage mode in northern Henan province based on the long-term experiment. 【Method】 This study was based on the long-term tillage experiment started from 2016, which included different combination of three tillage practices, rotary tillage, shallow rotary tillage, and deep tillage before winter wheat sowed. The different combinations were 3-year cycle. Five typical treatments were selected: (1) continuous rotary tillage (RT-RT-RT); (2) Deep tillage-rotary tillage-rotary tillage (DT-RT-RT); (3) Deep tillage-rotary tillage-shallow rotary tillage (DT-RT-SRT); (4) Deep tillage- shallow rotary tillage- shallow rotary tillage (DT-SRT-SRT); (5) Deep tillage- shallow rotary tillage-rotary tillage (DT-SRT-RT). During the wheat season in 2021, root growth indexes, wheat photosynthetic characteristics, total nutrients of all organs at maturity, soil porosity, soil bulk density, aggregate distribution and wheat yield were measured and analyzed. 【Result】 Compared with RT-RT-RT, the wheat root indexes were improved under the treatments with rotation tillage, therein, DT-SRT-RT displayed the outstanding one. The highest increment of root indexes was at jointing stage. The total root length (RL), surface area (SA), volume (RV), and diameter (RD) were increased by 80.8%, 54.1%, 51.5%, and 21.9%, respectively. The increment was decreased with wheat growth, with the relevant value as 39.0%-28.8% (RL), 21.7%-10.8% (SA), 12.4%-17.8% (RV), and 17.5%-24.5% (RD), respectively. Rotational tillage treatments promoted the wheat photosynthetic characteristics, similar as root indexes, while DT-SRT-RT was demonstrated the better effect among all the treatments. Compared with RT-RT-RT, under DT-SRT-RT, the net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) was increased by 25.7%, 41.5%, and 20.5% respectively, at the jointing stage, which was increased by 55.4%, 21.7%, and 17.4%, respectively, at the flowering stage. At the filling stage, the Pn and Gs were increased by 9.7% and 13.6%, respectively, while the Tr was decreased by 6.7%. The nutrient in wheat organ was promoted under the treatments with rotation tillage compared to RT-RT-RT. Therein, under DT-SRT-RT, the TN in leaves, stems, and roots was increased by 66.2%, 80.1% and 61.1%, respectively; the TP in leaves and stems increased by 31.2% and 38.4%; the TK in roots was increased by 50.0%. Compared with RT-RT-RT, the soil porosity was improved in the 20-30 cm soil layer with the increment of 27.1%. The treatments with rotation tillage decreased the soil bulk density in the 0-30 cm soil layer. Meanwhile, the aggregate size with >0.25 mm was increased under the treatments with rotation tillage, especially, it was significant increases under DT-SRT-SRT in the 0-20 cm soil layer. However, the silt and clay proportion were decreased under the treatments with rotation tillage. Additionally, the root-shoot (R/S) ratio, numbers of ears, grain number per spike, 1000-grain weight and yield under the treatments with rotation tillage were higher than those under RT-RT-RT. The R/S ratio increased by 55.6%, numbers of ears increased by 45.3%, and yield increased by 20.7% under DT-SRT-RT. The correlation analysis showed that the yield positively correlated with root length and Stomatal conductance and net photosynthetic rate. 【Conclusion】 In conclusion, the rotation tillage mode improved the soil porosity and root architecture, raised the photosynthetic rate, enriched the TN, TP, and TK in wheat organs, and increased wheat yield. Therein, the DT-SRT-RT demonstrated the better effect.

【Objective】 Investigating the impacts of different N application regimes on crop (spring maize) yield and nitrous oxide (N₂O) emission provided the basis for reasonable N (Nitrogen) application and GHG (Greenhouse Gas) emission mitigation in dryland farming of the Loess Plateau. 【Method】 In this study, the impacts of five N application regimes on spring maize (Xianyu 335) yield and N₂O emission were investigated in a short-term (2 years) experiment in Changwu Agro-Ecological Experimental Station, and the treatments included: no fertilizer; conventional N fertilization (Con, 250 kg N•hm^-2); optimized N fertilization (Opt, 200 kg N•hm^-2); optimized N fertilization with slow-release fertilizer (Opt+SR, 200 kg N•hm^-2); optimized N fertilization with dicyandiamide (Opt+DCD, 200 kg N•hm^-2). The N₂O emission fluxes were monitored using sealed static chambers, and the gas chromatograph and the global warming potential (GWP) was calculated. 【Result】 (1) N₂O emissions increased rapidly after N application, reaching a peak on the second day, and rapidly decreased after 10 days of maintenance. Optimized N fertilization significantly decreased N₂O emissions (P<0.05). Compared with Con, the reductions in N₂O emissions under Opt, Opt+DCD, and Opt+SR were 21.4%, 27.6%, and 26.0%, respectively. The GWP of N₂O emissions under Con, Opt, Opt+DCD, and Opt+SR were 425.01, 334.01, 307.83, and 314.57 kgCO₂-eq•hm^-2, respectively. Opt+DCD significantly reduced N₂O emission intensity by 27.8% than that under Con (P<0.05). (2) N₂O emissions were highly correlated with surface soil NH₄⁺-N content (P<0.01), but showed no significant correlation with soil moisture and temperature. (3) Compared with Con, Opt, Opt+DCD, and Opt+SR significantly improved N fertilizer agronomic efficiency (with increases of 25.5%, 25.7%, and 22.2%, respectively) and nitrogen fertilizer partial factor productivity (with increases of 29.9%, 28.7%, and 25.4%, respectively) (P<0.05), whereas they had no significant impact on spring maize yield. 【Conclusion】 In dryland farming of the Loess Plateau, reducing N fertilizer application, applying slow-release fertilizer, and adding nitrification inhibitors properly could promote N₂O emission reduction and increase spring maize yield. Notably, reducing N fertilizer application by 20% and adding nitrification inhibitors not only ensured spring maize yield but also had the best effect on N₂O emission reduction.

【Objective】 The aim of this study was to explore the comprehensive impact of integrated drip irrigation and nitrogen regulation on the growth, physiology, water-nitrogen utilization efficiency, yield, and fruit quality of apple trees in northern semi-arid regions, and to determine the optimal water-nitrogen regulatory system. 【Method】 The experimental design involved two regulatory factors: irrigation and fertilizer application. Three irrigation levels were set up, representing 75%-90% (W1), 60%-75% (W2), and 45%-60% (W3) of field water capacity, respectively. Four fertilizer application levels were set, with N-P₂O₅-K₂O of 18-12-6 g/plant (F1), 15-12-6 g/plant (F2), 12-12-6 g/plant (F3), and 9-12-6 g/plant (F4). The study analyzed the effects of different water-nitrogen treatments on the growth and physiological indicators, water-fertilizer utilization efficiency, dry matter, yield, and fruit quality of apple trees. With the objectives of water and fertilizer saving, as well as high yield and high quality, a comprehensive evaluation model was established by combining the AHP-CRITIC combination weight method and the TOPSIS model. 【Result】 Water-fertilizer coupling produced highly significant effects on plant growth, chlorophyll content (SPAD), irrigation water use efficiency (IWUE), fertilizer partial productivity (PFP), fruit weight and yield of apple trees, and significant effects on basal stem growth. Under different water-fertilizer coupling treatments, the moderate deficit of irrigation and nitrogen application treatments were more favorable to increase plant growth, basal stem growth, leaf area, dry matter, yield, water use efficiency (WUE), water productivity (WP), IWUE, FPP, and fruit weight of apple trees, and their maximums occurred in the F2W2 treatment. The SPAD, photosynthesis rate, and transpiration rate of apple trees increased with increasing amounts of irrigation and nitrogen, but the moderate deficit of irrigation and nitrogen application treatments had no significant effect on physiological indices, with the F1W2 and F2W1 treatments decreasing by only 3.5%, 3.1%, 7.7%, and 3.5%, 3.1%, and 3.8%, respectively, compared with F1W1. The AHP-CRITIC combination was used to determine the combination weights of the indicators, in which the weight of yield was the largest, amounting to 0.406, followed by vitamin C. The TOPSIS algorithm was used to construct a comprehensive multi-objective evaluation system for apples, and the result was that the comprehensive score under the F2W2 treatment was the highest, amounting to 0.8974, with the F1W2 and F2W1 treatments coming next, and the F4W3 treatment had the lowest score of 0.0177. The established interaction response model of coupled water and fertilizer in apples shows that the effects of both irrigation and fertilizer application on the composite score of apple growth were parabolic lines with downward opening. The apple growth composite scores showed a trend of increasing and then decreasing with increasing irrigation or fertilizer application, which was consistent with the diminishing reward effect, i.e., irrigation and nitrogen application exceeding a certain range and then continuing to increase would lead to a decrease in composite scores, which was not obvious for the improvement of apple growth. When the fertilizer application coded value X₁ was 0.681 and the irrigation coded value X₂ was 0.488, the highest apple composite score was 0.923, i.e., the fertilizer application rate was 34.56 g·plant^-1 (N-P₂O₅-K₂O: 16.56-12-6 g/plant), and the irrigation rate was controlled at 82.3% of field water capacity, so this irrigation and fertilizer application treatment was the most desirable for the growth of apples. 【Conclusion】 The comprehensive evaluation system constructed using the AHP-CRITIC-TOPSIS method could effectively determine the optimal water and nitrogen regulation system for apples, which provided a theoretical and practical basis for the actual production of apple orchards in northern semi-arid regions.

【Objective】 The phenotypic genetic diversity and taste performance of cultivated and wild tomato germplasm resources from around the world was analyzed, in order to screen specific and high-quality tomato resources, so as to provide the germplasm and theoretical support for the exploration of excellent tomato genes and tomato breeding. 【Method】 A total of 169 tomato resources collected domestically and internationally were used as the research object, and 38 phenotypic traits of them were measured throughout the entire growth period. The genetic diversity analysis, cluster analysis, and comprehensive evaluation of tomato germplasm phenotypes were conducted through multiple statistical analysis methods, such as genetic diversity index, principal component analysis, weight, systematic clustering, and membership function. 【Result】 The variation coefficient of phenotypic traits in 169 tomato samples ranged from 18% to 368%, and the genetic diversity index ranged from 0.036 to 2.302. There were 26 traits with a genetic diversity index >1, among which the genetic diversity index for mature fruit color was the highest (2.302), indicating that the 169 tomato samples in this study were diverse in type and rich in genetic diversity. Correlation analysis showed that tomatoes with the higher plant height, the more flowers per inflorescence, and the smaller fruits had a higher sugar-to-acid ratio. Principal component analysis showed that 16 phenotypic traits (single fruit weight, number of ventricles, fruit shoulder shape, fruit shoulder furrows, longitudinal and transverse diameters of fruits, ratio of sugar to acid, soluble solids, cork size, growth habits, plant height, second inflorescence node position, inflorescence type, mature fruit color, number of inflorescence flowers, and plant type) had a relatively large contribution rate to resource variation, and could be used as the main indicator for cluster analysis. The clustering analysis results showed that 169 tomato resources were divided into 10 major groups at a Euclidean distance of 5.0. The first and second groups were Solanum cheesmanii, the third and tenth groups were upright tomatoes with different fruit sizes, the fourth and fifth groups were ordinary large fruit tomatoes with unlimited growth, the sixth group was large fruit tomatoes in the upright type, the seventh and eighth groups were mostly cherry tomatoes and a small number of Solanum Pimpinellifolium, and the ninth group was limited growth large fruit tomatoes. Using the membership function method and weight analysis, a comprehensive evaluation was conducted on the taste and flavor of tomato fruits. Based on the D-value ranking of the comprehensive evaluation, 10 sweet and sour-tasting Solanum Pimpinellifolium and cherry tomatoes with good taste were selected, and 5 sweet, fleshy, and sandy-soft-tasting large fruit tomato resources were selected. 【Conclusion】 The research results clarified the phenotypic specificity and rich genetic diversity of 169 tomato germplasm resources. Cluster analysis screened out tomato resources specific to each group and used fruit taste-related indicators to screen cherry tomatoes and ordinary large fruit tomato resources for better performance. This study could serve as the theoretical and material basis for the genetic improvement of excellent tomato resources and new variety breeding.

【Background】 Non-heading Chinese cabbage (Brassica campestris L. ssp. chinensis (L.) Makino), a member of the Cruciferae family, is a leafy vegetable widely cultivated in the southern regions of China. Among leaf traits, the leaf wrinkling is a significant agronomic characteristic of non-heading Chinese cabbage. This trait not only determines the visual marketability of non-heading Chinese cabbage, but also significantly affects its yield, nutritional quality, stress resistance, and photosynthetic activity of the leaves. However, there is currently no clear understanding of the genetic and formation mechanisms of this trait, which limits efficient genetic improvement of this trait. 【Objective】 The objective of this study was to quantitatively describe the leaf wrinkling trait of non-heading Chinese cabbage, to explore its genetic and formation mechanisms, and to enhance the efficient selection and regulation of this trait, so as to consequently guide breeding efforts for non-heading Chinese cabbage. 【Method】 Six distinct F₂ populations were constructed using Tacai (Brassica campestris ssp. chinensis var. rosularis Tsen et Lee), which with conspicuous leaf wrinkling in non-heading Chinese cabbage as one of the parents. The leaf wrinkling trait of F₂ plants was quantified during the rosette stage using the indicator “number of bulges in the maximum leaf”. A genetic segregation analysis method for quantitative traits, incorporating both major gene and polygenic inheritance, was employed to investigate the genetic principles governing this trait. 【Result】 Significant variation was found among individual plants in the F₂ population regarding leaf wrinkling traits, manifesting as continuous changes. The distribution curve demonstrated a normal or skewed normal distribution, suggesting that leaf wrinkling in non-heading Chinese cabbage was a quantitative trait influenced by multiple genes. Genetic analysis of these traits was then conducted utilizing a major gene + polygene genetic model calculation method. The result showed that the optimal genetic model for leaf wrinkling in non-heading Chinese cabbage was the 2MG-ADI gene model, with a major gene heritability of 99.08%. The first major gene’s dominant effected mitigates wrinkling, while the second major gene’s dominant effect intensified it. Both major genes exhibited additive effects, deepening wrinkling. Additive × additive and additive × dominant interaction effects reduced wrinkling, whereas dominant × additive and dominant × dominant interaction effects enhanced the traits. 【Conclusion】 The leaf wrinkling trait in non-heading Chinese cabbage was a quantitative characteristic governed by two pairs of major genes, with these major genes predominantly influencing its regulation.

【Objective】 The study was conducted to investigate the effects of different replacement ratios of soybean meal (SBM) on its metabolizable energy and nitrogen metabolism in broilers. Furthermore, the relationship between uric acid and digestible nitrogen with soybean meal apparent metabolizable energy (AME) were analyzed for providing references for accurately measuring the metabolizable energy of feed ingredients. 【Method】 A completely randomized design was adopted, and the replacement ratio of SBM was treated as a single variable. A total of 216 broilers at aged 22 days were randomly divided into 6 groups, with replacement ratios of SBM at 10% (SM10), 20% (SM20), 30% (SM30), and 40% (SM40), while the other two groups were the basal diet 1 and basal diet 2. Each experimental diet was allocated to 6 replicates of 6 broilers per replicate. Metabolic trials were conducted on broilers aged 22-28 days. The total collection method was used to collect all excreta of each repetition as the experimental unit, the energy and protein content in both the feed and excreta matter and uric acid content in excreta were determined. These data were then used to analyze the relationship between uric acid and AME and nitrogen-corrected apparent metabolizable energy (AMEn) of soybean meal.【Result】 (1) Soybean meal replacement ratio had no significant effect on the total energy intake of broilers (P>0.05), but had a significant effect on the total energy output of broilers (P<0.05). As the soybean meal replacement ratio increased, the AME and AMEn of diets decreased significantly (P<0.05). (2) With the increase in soybean meal replacement ratio, the protein intake, protein output, uric acid excretion, retained nitrogen, and digestible nitrogen in broilers were significantly increased (P<0.05). (3) As the soybean meal replacement ratio increased, there was a significant increase in the output of uric acid per unit of protein intake (UAO/PI, g·g^-1, %) (P<0.05), as well as an increase in the excretion of uric acid nitrogen per unit of digestible nitrogen (UAN/DN, g·g^-1, %) (P<0.05). A significant linear relationship was observed, with increasing SBM replacement ratios leading to a decrease in AME and AMEn (P<0.05). (4) A strong negative correlation was observed between UAO/PI and UAN/DN with the AME and AMEn of SBM (R²>0.90, P<0.05).【Conclusion】 The tested soybean meal replacement ratios significantly affected nitrogen metabolism and metabolizable energy measurement in broilers. There was a significant negative correlation between uric acid excretion and metabolizable energy, so which make uric acid nitrogen a potential indicator for optimizing the metabolizable energy system.

【Objective】 Marbling is one of the key indicators for meat quality, formed by the joint development of bovine skeletal muscle cells and bovine adipocytes. The purpose of this study was to simulate the interaction effect of bovine skeletal muscle cells and adipocytes in the process of meat formation in vivo to the greatest extent, and to establish two cell co-culture systems in vitro to explore the regulatory effects of bovine skeletal muscle cell secretion and metabolic factors on adipocytes under the co-culture system.【Method】 Bovine adipocytes and skeletal muscle cells were isolated separately using tissue block and enzymatic digestion methods. Cells were identified for purity and differentiation potential by phenotypic identification and gene expression profiling, the conditioned medium exchange co-cultivation systems constructed further, and Transwell co-cultivation systems involving bovine skeletal muscle cells and bovine fat cells was conducted. The impact of secretory and metabolic products from bovine skeletal muscle cells on the proliferation and differentiation of fat cells under co-culture conditions was assessed using techniques, such as real-time quantitative PCR (qPCR), EdU staining, and Oil Red O staining. 【Result】 In this study, two co-culture systems of bovine skeletal muscle cells and adipocytes were successfully constructed. Under the condition of medium exchange co-culture, the expression of bovine fat cell proliferation marker genes, including PCNA, CDK2, CCNE2, and CCND1, was significantly downregulated (P<0.01). Additionally, the expression of adipogenesis marker genes FABP4 and PPARγ was significantly decreased (P<0.05); the expression of LPL was greatly reduced (P<0.01). On the other hand, in the Transwell co-culture system, the expression of the bovine fat cell proliferation marker gene CCND1 was significantly downregulated (P<0.05); the expression of PCNA, CDK1, and CCNE2 was greatly downregulated (P<0.01). Additionally, the expression of the adipogenesis marker gene FABP4 was significantly decreased (P<0.05), while the expression of PPARγ, C/EBPβ, and LPL was extremely significantly decreased (P<0.01). 【Conclusion】 The results of this study indicated that secretory and metabolic products from bovine skeletal muscle cells could suppress the proliferation and differentiation of bovine adipocytes by inhibiting the expression of proliferation marker genes, including PCNA, CDK1, CDK2, CCNE2, and CCND1, as well as lipogenic marker genes, such as PPARγ, FABP4, CEBPβ, and LPL. The results of this study indicated that secretory and metabolic products from bovine skeletal muscle cells could suppress the proliferation and differentiation of bovine adipocytes by inhibiting the expression of proliferation marker genes, such as PCNA, CDK1, CDK2, CCNE2 and CCND1, as well as lipogenic marker genes, such as PPARγ, FABP4, CEBPβ and LPL.