【Objective】 This study aimed to clarify the regulatory effects of the reduced nitrogen combined with controlled water, biochar, and the nitrification inhibitor dicyandiamide (DCD) on nitrogen losses within a facility soil-tomato system, so as to provide a scientific basis for efficient nitrogen use and sustainable green development in facility vegetable production.【Method】 A field plot experiment was conducted using facility tomato as the research object, with two irrigation treatments including traditional drip irrigation (TD) and reduced drip irrigation (CD). Based on this, eight nitrogen treatments were designed, including no nitrogen (TDN0, and CDN0), traditional nitrogen (TDN1, and CDN1), reduced nitrogen (TDN2, and CDN2), and reduced nitrogen combined with biochar and dicyandiamide (DCD) (TDN2+BD, and CDN2+BD). During the topdressing period, soil N₂O emission and NH₃ volatilization, NO₃^--N accumulation in the 0-100 cm soil profile, and tomato nitrogen uptake, yield, and fruit quality indicators were systematically monitored to quantitatively evaluate the synergistic regulatory effects of biochar and DCD under reduced nitrogen and controlled water conditions. 【Result】 Nitrogen application significantly increased soil N₂O emissions and NH₃ volatilization, with peak fluxes occurring 2-3 days after topdressing. Nitrogen reduction effectively suppressed gaseous nitrogen losses, and the combined application of biochar and the nitrification inhibitor DCD further enhanced the mitigation effect on N₂O emissions. Although biochar and DCD posed a potential risk of increasing NH₃ volatilization, this adverse effect was substantially alleviated by reduced nitrogen and controlled water conditions. Compared with conventional nitrogen application, nitrogen reduction significantly decreased total gaseous nitrogen losses by 45.7%-56.6% and reduced NO₃^--N accumulation in the 0-100 cm soil profile by 13.7%-16.2%. When biochar and DCD were applied on the basis of nitrogen reduction, total gaseous nitrogen losses further declined by 49.4%-59.0%, while the reduction in NO₃^--N accumulation expanded to 27.4%-30.0%, with a clear suppression of deep leaching. Both irrigation methods enhanced the synergistic mitigation effects of water nitrogen regulation. However, controlled drip irrigation demonstrated superior performance compared with conventional drip irrigation. Under controlled irrigation, the CDN2+BD treatment reduced total nitrogen losses by 30.0% compared with CDN1, with decreasing the net nitrogen loss rate from 3.3% to 2.5%. This treatment also significantly inhibited deep NO₃^--N accumulation and increased NO₃^--N retention in the 20-40 cm soil layer by 27.1%. In addition, biochar and DCD increased the apparent nitrogen use efficiency under controlled irrigation to 28.9%; TDN2+BD and CDN2+BD improved nitrogen use efficiency by 53.0% and 30.2%, respectively, compared with their corresponding nitrogen-reduction treatments (TDN2 and CDN2) (P<0.05). Furthermore, the controlled irrigation with biochar and DCD (CDN2+BD) achieved the highest tomato yield (115.93 t·hm^-2), while significantly enhancing fruit vitamin C content and improving soluble protein, soluble sugar, and total soluble solid levels.【Conclusion】 Reduced nitrogen application combined with controlled water, biochar, and the nitrification inhibitor dicyandiamide (DCD) significantly decreased gaseous and leaching nitrogen losses, optimized soil nitrogen distribution, and improved nitrogen use efficiency and tomato quality, representing an optimal technical approach for nitrogen reduction and efficiency enhancement in facility vegetable production.

【Objective】 To investigate the molecular mechanisms underlying black-tailed and white-tailed feather coloration in Babcock B380 and to identify key candidate genes and loci associated with tail feather color. It provides a theoretical basis for poultry breeding and molecular breeding of feather color related traits.【Method】 A natural population consisting of 80 Babcock B380 hens with either black-tailed or white-tailed phenotypes was used in this study. The morphology and distribution of melanosomes within tail feather follicles were analyzed using histological sections observed under light microscopy and transmission electron microscopy. Transcriptome data were utilized to identify differentially expressed genes (DEGs), and weighted gene co-expression network analysis (WGCNA) was performed to identify co-expression modules associated with tail feather color and to screen hub genes within key modules. The expression levels of selected DEGs were subsequently validated by quantitative real-time PCR (qRT-PCR). Furthermore, based on genotypic data from the natural population, a genome-wide association study (GWAS) was conducted to identify genetic loci associated with black-tailed and white-tailed feather coloration in Babcock B380 chickens. The identified loci were further validated at the population level and subjected to integrative analysis. In addition, codon usage bias of PMEL mRNA was analyzed.【Result】 Microscopic observations revealed that melanosomes were predominantly deposited in the feather shaft region of chicken feather follicles, with the melanosome area being significantly greater in black-tailed chickens than in white-tailed chickens. Transcriptome analysis identified 373 DEGs, which were significantly enriched in melanin biosynthesis- related pathways. Key pigmentation-related genes, including PMEL, TYR, TYRP1, and SLC45A2, were highly expressed in black-tailed feather follicles. Weighted gene co-expression network analysis (WGCNA) identified 25 co-expression modules, among which the MEmagenta module was closely associated with melanosome biosynthesis. Integrated analyses of network connectivity and protein-protein interaction networks identified ten potential hub regulatory genes: PMEL, PIAS2, NDEL1, MSRA, HDLBP, GCNT4, FMR1NB, TBLX1, ST3GAL5, and RAB11A. qRT-PCR validation showed that the expression patterns of 4 DEGs were consistent with the RNA-seq results. GWAS identified a total of 968 significant SNPs located on chicken chromosomes 1, 5, and 34, which were annotated to 221 genes. Among these, 7 SNPs within the PMEL gene showed significant associations with tail feather color. Notably, the rs316665588 locus was significantly associated with black-tailed and white-tailed feather phenotypes. Codon bias index (CBI) analysis indicated that the mutation at this locus resulted in a transition from the rare codon UGU to the more frequently used codon UGC.【Conclusion】 The melanosome distribution area in feather follicles was significantly larger in B380 black-tailed chickens than in their white-tailed counterparts. Transcriptome analysis identified 4 key DEGs associated with plumage coloration and revealed 10 potential hub regulatory genes. PMEL was identified as a candidate gene underlying the black-tailed and white-tailed phenotypes in B380 chickens, and the synonymous T/C mutation at rs316665588 represents a key candidate locus contributing to the formation of black/white tail plumage.

【Objective】 Intercropping maize with leguminous green manure can achieve fertilizer conservation and efficiency improvement. Biochar application is an effective measure to mitigate gaseous nitrogen loss form farmland. However, the impacts of nitrogen reduction under intercropping green manure combined with the biochar application on gaseous nitrogen loss and the system’s nitrogen footprint remain unclear. This study aimed to evaluate this comprehensive practice to provide a technical approach for the green maize production in oasis irrigation areas of Northwest China. 【Method】 A two-factor field experiment was set up in 2021 at Wuwei Oasis Agricultural Experimental Station in Gansu Province. The experiment employed a two-factorial design. The main factor was nitrogen application system, including conventional nitrogen application (N100), 30% nitrogen reduction (N70), and 30% nitrogen reduction combined with sesbania biochar (N70S). The second factors were cropping patterns, including maize monoculture (MM) and maize intercropping with common vetch (IMC). Six treatments were formed: N100-MM, N100-IMC, N70-MM, N70-IMC, N70S-MM, and N70S-IMC. From 2024 to 2025, maize yield, nitrogen absorption and soil physicochemical properties were measured, nitrous oxide emission and ammonia volatilization were monitored, and the nitrogen footprint of the system was quantified by life cycle assessment method. 【Result】 Compared with N100, N70 decreased maize grain yield, aboveground biomass and nitrogen absorption by 7.9%, 6.1% and 4.7%, respectively. In contrast, N70S increased grain yield and biomass by 8.6% and 2.7%, respectively. IMC increased the yield by 3.8% compared with MM. Notably, N70S-IMC increased grain yield, aboveground biomass and nitrogen absorption by 12.6%, 4.3% and 4.0%, respectively, compared with N100-MM. The N70 reduced cumulative N₂O emissions and NH₃ volatilization by 16.0% to 25.2% and 9.9% to 24.7%, respectively, relative to N100. The N70S further reduced these emissions by 24.8% to 27.7% and 17.6% to 43.9%, respectively. Compared with N100-MM, N70-IMC and N70S-IMC reduced cumulative N₂O emissions by 12.1% to 20.1% and 20.1% to 35.8% and NH₃ volatilization by 15.3% to 24.3% and 11.2% to 20.1%, respectively. Soil analysis showed that, compared with N100-MM, N70-IMC decreased soil ammonium nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃^--N), and microbial nitrogen (MBN) by 17.6%, 15.6%, and 9.6%, respectively. While N70S-IMC decreased NH₄⁺-N and soluble organic nitrogen (DON) by 15.6% and 7.3%, respectively, but increased total nitrogen (TN) and MBN by 3.9% and 25.0%, respectively. Random forest analysis indicated that soil NO₃^--N, NH₄⁺-N, MBN and DON were the key factors driving N₂O emissions, while NH₃ volatilization was mainly driven by NO₃^--N, NH₄⁺-N and TN. Life cycle assessment indicated that the nitrogen footprint under N70-IMC and N70S-IMC was decreased by 28.9% and 39.7%, respectively, compared with the N100-MM. Furthermore, the nitrogen footprint of the N70S-IMC treatment was 10.4% lower than that under N70-MM. 【Conclusion】 The combination of maize-green manure intercropping, 30% nitrogen reduction, and sesbania biochar application increased grain yield and nitrogen absorption, improved key soil properties, and lowered N₂O emissions, NH₃ volatilization, and the system’s nitrogen footprint, which was an effective path for green and sustainable maize production in the Northwest Oasis Irrigation District.

【Objective】 As a ruminant animal, cattle has a long muscle growth and development cycle. However, the regulatory mechanism of chromatin accessibility on bovine longissimus dorsi is not clear during the development of longissimus dorsi. This study aimed to explore the differential chromatin accessibility of the longissimus dorsi muscle of Angus cattle and Simmental cattle, screen the key transcription factors affecting bovine muscle growth, and then construct the TF-gene regulatory network, so as to provides the theoretical basis and new molecular target for further study of the epigenetic regulation mechanism of bovine muscle development.【Method】 The longissimus dorsi muscle tissues of 24-month-old Angus cattle (AGS) and Simmental cattle (XM) with the same feeding and management methods were collected, and the amino acid content was detected according to the national standard Determination of amino acids in food (GB 5009.124-2016). SPSS 9.4 software was used to analyze the significant difference of amino acid content in longissimus dorsi muscle between groups by t test. The collected longissimus dorsi muscle tissue was subjected to ATAC-seq sequencing. By identifying the chromatin open area (peak), peak analysis, GO/KEGG functional enrichment analysis, and transcription factor binding site (motif) enrichment analysis were performed. Combined with the differentially expressed genes (DEGs) obtained from the previous RNA-seq sequencing, a transcription factor-gene (TF-gene) regulatory network was constructed based on the GTRD database and the OmicShare Tools.【Result】 The results showed as follows：(1) The content of lysine (Lys), serine (Ser), arginine (Arg), histidine (His) and glutamic acid (Glu) in longissimus dorsi muscle of AGS group were significantly higher than those of XM group (P < 0.05); the content of proline (Pro) was the opposite (P < 0.05), indicating that the amino acid metabolic phenotype was significantly different between the two groups. (2) Chromatin accessibility was generally conserved between the two groups. A total of 29 140 peaks were detected in Angus cattle and 28 781 peaks were detected in Simmental cattle. The chromatin open regions between the two groups were mainly distributed at the transcription start site (TSS) ± 2 kb, and accounted for more than 84.57 % in the intron region, distal intergenic region and promoter region. (3) A total of 6 185 differential peaks were identified between the two groups, of which 5 030 peaks were up-regulated and 1155 were down-regulated. After the differential peak were annotated to related genes, GO/KEGG enrichment analysis showed that the differential peak-related genes were mainly enriched in classical muscle development-related pathways, such as anatomical morphogenesis, muscle structure development, actin filament-mediated, Hippo signaling pathway, MAPK signaling pathway, calcium signaling pathway, and actin cytoskeleton regulation. (4) Motif enrichment analysis showed that among the top 20 transcription factor binding motifs, the top four belonged to the MEF2 transcription family, which were MEF2C, MEF2A, MEF2D, and MEF2B, respectively. Further focusing on the intersection analysis of AGS-specific peak and differentially expressed genes obtained by previous RNA-seq sequencing, it was found that the binding sites of MEF2B and MEF2D were the most enriched, and the TF-gene regulatory network with MEF2B and MEF2D as the core transcription factors was successfully constructed. A total of 13 target genes involved in muscle development regulation were screened, including ACTA1, CKM, CLCN1, SLN, and MYOZ3. IGV visualization confirmed the presence of MEF2B and MEF2D binding motifs in the promoter region of the above target genes, and highly overlapped with the open region of ATAC-seq.【Conclusion】 In this study, the combined analysis of ATAC-seq and RNA-seq data revealed the differences in chromatin accessibility between Angus cattle and Simmental cattle during the development of longissimus dorsi muscle, and screened MEF2B and MEF2D as key transcription factors (TFs) regulating bovine muscle growth. The TF-gene regulatory network with MEF2B and MEF2D as core transcription factors was constructed, which provided a theoretical basis for further analysis of the epigenetic mechanism of muscle development in beef cattle and functional verification of CRISPR-Cas9.

【Objective】 To evaluate the contributions of source, flow and sink traits to soybean yield, clarify the relationships among these traits during yield formation, reveal the key physiological mechanisms underlying soybean yield formation, and provide a theoretical basis for soybean breeding. 【Method】 Qihuang 34, Lindou 9, Weidou 9, and Hedou 12 were investigated during the pod-setting and seed-filling stages. The photosynthetic performance, assimilate partitioning, and dry matter accumulation were analyzed throughout plant development by using ¹³C isotope labeling. Source-flow-sink traits were comprehensively evaluated, and radar chart analysis was applied to characterize the coordination of these traits among cultivars during yield formation.【Result】 (1) The correlations between source, flow and sink traits and yield varied considerably. The contributions of these traits to yield ranked as follows: leaf area index > 100-seed weight > net photosynthetic rate > palisade tissue thickness > effective quantum yield of PSII (ΦPSII) > glutamine synthetase activity > glutamate synthase activity > mean sieve tube diameter > stomatal conductance > midrib diameter. (2) Significant interactions were observed among source, flow and sink traits. Source-sink interactions were reflected by positive correlations of net photosynthetic rate, stomatal conductance and transpiration rate with 100-seed weight. Source-flow interactions were indicated by positive correlations of palisade tissue thickness and leaf thickness with net photosynthetic rate, whereas flow-sink interactions were represented by a positive correlation between mean sieve tube diameter and 100-seed weight. (3) Source, flow and sink traits differed markedly among cultivars. Qihuang 34 exhibited higher leaf area index, palisade tissue thickness, leaf thickness, net photosynthetic rate, ΦPSII, sustained dry matter accumulation in main stem pods, yield, 100-seed weight, glutamine synthetase activity, glutamate synthase activity, 3-day assimilate translocation to main stem pods and sustained assimilate translocation than the other three cultivars. Hedou 12 showed the largest midrib diameter, Weidou 9 had the highest seed number per plant, and Lindou 9 exhibited the greatest carbon assimilation capacity of branch pods. These results indicate that high soybean yield depends on the coordinated regulation of source, flow and sink traits rather than on any single trait.【Conclusion】 Among the four cultivars, Qihuang 34 achieved the highest yield owing to its larger leaf area index, stronger assimilate transport capacity, and greater 100-seed weight. Breeding high-yield soybean cultivars with coordinated source, flow and sink characteristics should prioritize germplasm with high photosynthetic efficiency based on ΦPSII, net photosynthetic rate and leaf area index, followed by evaluation of assimilate transport efficiency using leaf and vascular bundle anatomical traits and assessment of yield potential through nitrogen metabolism enzyme activities and sink capacity.