【Objective】Grain shape is an important agronomic trait affecting rice yield and quality, and its development is regulated by the three-dimensional morphology of grain (grain length, grain width, grain thickness). Identification and cloning of grain shape regulatory genes can enrich the molecular mechanism of rice grain development regulation, and provide theoretical basis and genetic resources for high-yield molecular design breeding of rice. 【Method】A stable inherited grain type mutant sgd13 (small grain and dwarf 13) was screened from the mutant library of Nanjing 9108 induced by ethyl methane sulfonate (EMS). The grain morphology, 1000-grain weight, seed setting rate, yield per plant, plant height, panicle length and other phenotypes of the mutants were statistically analyzed. Paraffin sections and scanning electron microscopy were used to analyze the changes in the number and size of glume and stem cells. The genetic analysis of sgd13 and Nanjing 9108 was carried out. The F₂ population constructed by sgd13 and Nanjing 9108 was used to locate the gene by BSA-seq technology. The SWISS-MODEL website was used to predict the three-dimensional structure of wild-type and mutant proteins. 【Result】The grains of sgd13 were significantly smaller and narrower, the grain length decreased by 19.98%, and the grain width decreased by 7.81%. Compared with WT, the plant height, spike length and yield per plant of sgd13 were significantly reduced. There was no significant difference in the number of internodes between sgd13 and WT, but the lengths of the first, second, third and sixth internodes were shorter. Cytological analysis showed that the glume and stem cells of sgd13 became smaller and less, indicating that sgd13 may affect organ development by regulating cell division and expansion. Genetic analysis confirmed that the trait was controlled by a single recessive nuclear gene. The candidate gene was mapped to LOC_Os01g52550 by BSA-seq, which encodes an ATP-binding cassette (ABC) transporter. The ABC transporter contains two typical core domains: A highly conserved nucleotide binding domain (NBD) and a less conserved transmembrane domain (TMD). In the sgd13 mutant, a single base substitution (T→A) occurred in the exon region of the gene, which was located in the NBD domain. This single base substitution directly causes the encoded amino acid to change from glutamic acid (E) to aspartic acid (D). Due to the differences in side chain structure and chemical properties between glutamic acid and aspartic acid, this change is likely to affect the spatial structure of SGD13 protein, thereby interfering with its normal function, and ultimately leading to a unique phenotype of the mutant sgd13. Genetic complementation experiments showed that the introduction of wild-type LOC_Os01g52550 could restore the grain shape of sgd13 to the wild-type level.【Conclusion】The sgd13 mutant phenotype was controlled by a single recessive nuclear gene, which was caused by the LOC_Os01g52550 mutation. The T→A mutation in the exon region of the gene causes the glutamic acid in the NBD domain to become aspartic acid, which affects the three-dimensional structure of the protein.

【Objective】Low molecular weight gluten subunits (LMW-GS) are crucial components in determining the end-use quality of common wheat. Elucidating the diversity and impact on flour quality of LMW-GS is essential for genetic improvement in wheat.【Method】A collection of 421 Shanxi wheat accessions was utilized to identify allelic variations in the Glu-A3 and Glu-B3 using 18 specific markers. The polymorphism, genetic diversity, and cluster analysis of these alleles in Shanxi wheat was then conducted. Additionally, the effects of these alleles on the physicochemical quality, farinograph and extensograph properties, as well as dough viscosity characteristics of flour were investigated.【Result】The allelic variations in the Glu-A3, by frequency, are Glu-A3b, Glu-A3c, Glu-A3g, Glu-A3d, Glu-A3f, Glu-A3a, and Glu-A3e. At the Glu-B3, the identified allelic variations are Glu-B3g, Glu-B3a, Glu-B3d, Glu-B3i, Glu-B3b, Glu-B3h, Glu-B3e, Glu-B3c, and Glu-B3f. The genetic distance range for Shanxi wheat is 0.000 to 0.667, with a mean value of 0.253. It was observed that cultivars exhibited a greater genetic distance than landraces. Geographical distribution and irrigation/dryland types also influenced the genetic diversity of LMW-GS. Correlation analysis revealed that six LMW-GS allelic variations significantly correlated with five physicochemical quality traits. Glu-A3b, Glu-A3d, and Glu-B3i had negative effects on protein content, while Glu-A3b and Glu-B3i had positive effects on starch content. Glu-A3d and Glu-B3i showed positive effects on fiber content, and Glu-B3i increased the whiteness value of flour by 2.10%. Fifteen LMW-GS allelic variations were identified as significantly correlated with 12 processing quality traits, with Glu-A3e and Glu-B3d increasing extensibility by 36.71 and 19.91 mm, respectively. Glu-A3a, Glu-B3b, and Glu-B3e had positive effects on improving development time, stability time, stretch area, extension resistance, stretch ratio, and farinograph quality. Five LMW-GS subunits were significantly correlated with dough viscosity characteristics, with Glu-A3a increasing peak viscosity by 183.19 cp and the pad abort value by 67.79 cp.【Conclusion】LMW-GS alleles in Shanxi wheat exhibited high polymorphism. Geographical distribution and accession types affected the genetic diversity at the Glu-A3 and Glu-B3 loci. Six, fifteen, and five LMW-GS allelic variations were identified as showing significant correlations with flour physicochemical, processing quality, and dough viscosity traits, respectively.

【Objective】Saline-alkali stress is one of the significant abiotic stresses that restrict soybean production. Nicotinamide enzyme gene GmNIC1 is a key enzyme gene involved in the synthesis of NAD⁺ in soybeans. It has been previously established that this gene participates in abiotic stress responses. Investigating the function of GmNIC1 under saline-alkali stress lays the foundation for soybean breeding for saline-alkali tolerance.【Method】Using the soybean cultivar Hefeng 25 as the receptor, GmNICl-OE (overexpression) and GmNICl-KO (knockout) transgenic T₃ generation soybean plants were generated, and their growth and physiological indicators under saline-alkali stress were measured. Transcriptome sequencing was performed on wild-type (WT), GmNICl-OE, and GmNICl-KO plants, followed by GO functional enrichment and KEGG pathway enrichment analysis. A protein-protein interaction network was constructed based on the differentially expressed genes of the three comparative combinations, and proteins interacting with GmNIC1 were identified and validated using quantitative real-time PCR.【Result】After saline-alkali stress, GmNICl-OE plants exhibited yellowing of newly grown leaves but erect petioles and increased plant height; GmNICl-KO plants showed wilted and dried leaves, severed yellowing of stems and near-death: WT plants had yellowish-brown stems and leaves that were less yellowed and wilted than those of the GmNICl-KO plants. Compared to WT and GmNICl-KO plants, GmNIC1-OE plants showed increased NAD⁺ content and decreased NADP⁺ content, leading to glucose accumulation, increased activity of SOD and CAT enzymes, and reduced O₂^- and H₂O₂ content. Transcriptome sequencing revealed a total of 747 differentially expressed genes in the OE-1 vs KO-1 comparative combination, including 622 upregulated and 125 downregulated differentially expressed genes. The number of differentially expressed genes in this combination was significantly higher than that in the other two groups. The functions of differentially expressed genes in the three comparative combinations were mainly concentrated in lactase activity, transcriptional regulation activity, and oxidoreductase activity (acting on NADP (H)); metabolic pathways were mainly involved in the biosynthesis of secondary metabolites, exogenous substance metabolism, glucosinolate biosynthesis, galactose metabolism, MAPK signaling pathway, glutathione metabolism, etc. Four proteins related to GmNIC1 were identified, suggesting that Glyma.04G055000.1 positively interacts with GmNICl, and Glyma.12G086500.1 negatively interacts with GmNIC1.【Conclusion】GmNIC1 increases NAD⁺ content and reduces NADP⁺ content to accumulate glucose and enhance antioxidant enzyme activity to eliminate ROS, thereby strengthening the plant's resistance to salt and alkali stress. The GmNIC1 protein can also collaborate with Glyma.04G055000.1 and Glyma.12G086500.1 to jointly regulate the growth of soybean seedlings under salt and alkali stress.

【Objective】This study aimed to explore the suitable planting density of maize in the southern foothills of the Greater Khingan Mountains under multi-factor management and tap its yield potential, for providing a theoretical basis to reasonably select varieties under high-density planting conditions.【Method】Relying on the variety screening and density gradient experiments carried out in the Agricultural Science and Technology Demonstration Park of Zhalaite Banner from 2022 to 2024, a total of 4 planting densities, namely 7.2×10⁴, 8.3×10⁴, 9.2×10⁴ and 10.4×10⁴ plants/hm², were selected and divided into 3 density gradients: low density (7.2×10⁴ plants/hm²), medium density (8.3×10⁴ and 9.2×10⁴ plants/hm²), and high density (10.4×10⁴ plants/hm²). A total of 138 maize varieties and 252 samples were used. Data analysis was conducted on the plants height, ear position, lodging index, ear formation rate, yield, and yield-contributing factors of each sample.【Result】There was an extremely significant correlation between yield-contributing factors and planting density (P<0.01). There was a linear regression relationship between the number of harvested ears and the planting density, and its regression equation was y=0.765x+0.8577, with R² being 0.4986. Therefore, it could be predicted that between 7.2×10⁴ and 10.4×10⁴ plants/hm², for every 2×10⁴ plants/hm² increase in planting density, the number of harvested ears increases by 2.39×10⁴ ears/hm². There was an extremely significant correlation between yield and planting density (P<0.01). The yield showed an increasing trend with the increase in planting density. Compared with the average yield at low density, the yields of maize at high and medium densities increased significantly by 16.85% and 8.68%, respectively (P<0.05). There was a significant negative correlation between the ear formation rate and the planting density (P<0.05). The ear formation rate ranged from 85.53% to 90.46%, with an average of 87.08%. The yield increase slowed down after the number of harvested ears reached 8.62×10⁴ ears/hm². Based on calculation of the average ear formation rate of 86.01% at high planting density, the maximum planting density in the southern foothills of the Greater Khingan Mountains should not exceed 10.02×10⁴ plants/hm². There was an extremely significant negative correlation between planting density and plants height (P<0.01), and there was no correlation between planting density and ear position height or the ear position height coefficient. When the plants height was ≥314 cm, maize began to lodge. Within the range of 314-404 cm, for every 15 cm increase in plants height, the lodging degree increased by 3.88%. At low planting density, there was a significant positive correlation between the number of grains per ear, 100-grain weight, and yield (P<0.05). At medium density, there was an extremely significant positive correlation between the number of harvested ears, 100-grain weight, and yield (P<0.01). At high density, there was no significant correlation between yield and each factor. The impact of planting density on yield was greater than that of lodging degree. The lodging of maize caused by changes in planting density mainly affected the yield by influencing the number of harvested ears per mu, while the lodging of maize caused by the increase in plants height mainly affected the yield by influencing the number of grains per ear.【Conclusion】In the southern foothills of the Greater Khingan Mountains, when the planting density was low, varieties with a high number of grains per ear and high 100-grain weight should be selected to ensure maize yield. When the density was increased to 8.3×10⁴-9.2×10⁴ plants/hm², the ear formation rate should be improved as much as possible to ensure the number of harvested ears. When the planting density was further increased, on the basis of selecting density-tolerant varieties and ensuring the number of harvested ears, precise management should be carried out to ensure the balanced development of each yield-contributing factor, so as to obtain an ideal yield. However, the maximum planting density should not exceed 10.02×10⁴ plants/hm². Meanwhile, when the plants height of the planting variety was ≥314 cm, measures should be taken to prevent lodging.

【Objective】The purpose of this study was to elucidate the regulatory mechanisms of planting density on fertilization and kernel-setting characteristics in summer maize under drip fertigation conditions, and to clarify the relationship between planting density and kernel number per ear as well as yield formation under integrated water-fertilizer management.【Method】In 2023-2024, this experiment selected the medium-large ear type maize variety Denghai 605 (DH605) and the small ear type maize variety MY73 as test materials. It set up a traditional water and fertilizer management method (QG) with border irrigation and one-time base application of fertilizer before sowing, as well as a drip irrigation integrated water and fertilizer management method (DG). With a gradient of 15 000 plants/hm², a total of 8 planting densities ranging from 15 000 to 120 000 plants/hm² were set up to explore the impact of planting density on the fertilization and seed-setting characteristics and yield formation of summer maize under the integrated water and fertilizer management of drip irrigation.【Result】Compared with the QG treatment, the plant height and specific leaf area density (SDLA) of both DH605 and MY73 varieties increased under QG treatment, and the differentiation process of male and female spikes accelerated. The number of florets on the male spike increased, while the abortion rate decreased. The number of filaments, total florets, and fertilized florets on the female spike increased, and the seed setting rate and total seed setting rate improved too. The anthesis-silking interval (ASI) shortened by about 1 day, the empty spike rate decreased, and the maximum yields increased by 7.6% and 6.4%, respectively. Under different water and fertilizer management conditions, as planting density increased, the plant height and SDLA of both varieties increased, but the development of male and female spikes was inhibited: the number of florets on the male spike decreased, and the abortion rate increased; the number of silk-spinning and fertilized florets on the female spike decreased, and the fertilization rate and total fertilization rate of florets first increased and then decreased; under high-density conditions, the ASI extended by about 1 day, the empty spike rate and bald tip length increased, and the yield showed a trend of first increasing and then decreasing. In addition, the differentiation process of male and female spikes in MY73 was faster than that in DH605, with a shorter ASI, lower plant height, and larger SDLA. The decrease in the seed setting rate and total seed setting rate with increasing SDLA was not significant, and the planting density for achieving maximum yield was higher.【Conclusion】Under the conditions of this experiment, excessive planting density would have a significant negative impact on fertilization and fruiting characteristics, thereby affecting the establishment of grain number per ear and hindering yield improvement. Compared with traditional irrigation methods, drip irrigation water fertilizer integration technology could effectively alleviate the negative impact of high-density conditions on the fertilization and fruiting characteristics of summer maize, thereby increasing yield. DH605 and MY73 reached their maximum yields at planting densities of 60 000 plants/hm² and 75 000 plants/hm², respectively.

【Background】Rice blast, caused by Magnaporthe oryzae, is a devastating fungal disease that seriously threatens rice yield. Benzovindiflupyr developed by Syngenta belongs to the new structure of succinate dehydrogenase inhibitors (SDHIs) fungicides, which has a significant inhibitory effect on M. oryzae, but the research on the resistance mechanism of M. oryzae is relatively scarce.【Objective】This study aims to explore the internal mechanism of M. oryzae against benzovindiflupyr, and to provide a theoretical basis for scientifically guiding the application of benzovindiflupyr in the prevention and control of rice blast, prolonging its effective service life and ensuring the control effect.【Method】Homology comparison, molecular docking and site-directed mutagenesis were used to explore the reasons for the difference in sensitivity of M. oryzae to different SDHIs fungicides (benzovindiflupyr, bixafen, fluxapyroxad, carboxin and fluopyram), and the effect of amino acid substitution at different sites on the affinity of benzovindiflupyr to M. oryzae was analyzed.【Result】75 strains of M. oryzae collected in the field were highly sensitive to benzovindiflupyr, with an average EC₅₀ value of 0.041 μg·mL^-1, which was distributed between 0.018 and 0.068 μg·mL^-1. The interaction between five SDHIs fungicides and MoSdh was different, including hydrogen bonding, π-π stacking and hydrophobic interaction. The affinity of these fungicides to MoSdh from high to low was benzovindiflupyr, bixafen, fluxapyroxad, carboxin and fluopyram, which corresponded to the EC₅₀ values of these five SDHIs fungicides to M. oryzae (from low to high). A total of 15 types of amino acid substitutions were found in the 8 sites of the succinate dehydrogenase complex of M. oryzae. Among them, 7 sites such as B subunit P198 were highly conserved, while the amino acids at the S77 site in the C subunit were species-specific. Most of the substitutions affected the binding affinity of benzovindiflupyr to MoSdh (mainly related to hydrophobic interaction and π-π stacking number). Among them, 11 substitutions such as MoSdhB^P198Q and MoSdhB^R243H resulted in a decrease in affinity, and the sensitivity of SdhB^H245D/L/Y mutant to benzovindiflupyr decreased, which was consistent with the change of affinity.【Conclusion】Molecular docking technology can be used as an effective method to preliminarily screen SDHIs fungicides with prevention and control effects on M. oryzae. Amino acid substitutions in B, C and D subunits of M. oryzae, including MoSdhB^P198Q, MoSdhB^R243H, MoSdhB^H245D/L/Y/Q, MoSdhB^I247V/N, MoSdhC^S77N, MoSdhD^D122G/N, can lead to resistance of M. oryzae to benzovindiflupyr.

【Objective】This study aimed to explore the effects of GFabV on photosynthetic characteristics in ‘Shine Muscat’ grapevines under different Zn levels, and to elucidate the molecular mechanism of GFabV affecting leaf photosynthetic efficiency by analyzing the relative expression differences of photosynthesis-related genes.【Method】‘Shine Muscat’ grapevines infected with GFabV were treated with Zn-sufficient (0.22 mg·L^-1) and Zn-deficient (0) Hoagland nutrient solution, respectively, and virus-free plants were used as control. The symptom of grapevine leaves was observed, and Zn content, GFabV expression level, photosynthetic parameters, chlorophyll fluorescence parameters, and chlorophyll content in the leaves were measured. Differentially expressed genes (DEGs) related to photosynthesis were screened, and expression level of key genes was verified.【Result】Under Zn deficiency, the Zn contents in the leaves of plants infected with GFabV and virus-free plants were 1.79 and 9.59 mg·kg^-1, respectively, and the Zn contents of those under Zn sufficiency were 18.84 and 23.16 mg·kg^-1, respectively. The leaves of plants infected with GFabV showed shrinkage leaflets, and slight chlorosis symptoms under Zn deficiency, and GFabV relative expression was significantly higher than that of the leaves infected with GFabV under Zn sufficiency. The leaves of plants infected with GFabV did not show symptoms under Zn sufficiency. The leaves of virus-free plants showed slight chlorotic symptoms under Zn deficiency. In comparison to the virus-free plants treated with Zn sufficiency, the contents of Chla, Chlb, Chla+b, Fv/Fm and ΦPSII in leaves of the plants infected with GFabV and the virus-free plants under Zn deficiency were significantly decreased. The chlorophyll (a, b, a+b) contents, Fv/Fm and ΦPSII in the leaves of the plants infected with GFabV under Zn deficiency were the lowest, which were 1.22, 0.35, 1.57 mg·g^-1, 0.40 and 0.04, respectively. The net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs) of the plants infected with GFabV and the virus-free plants under Zn deficiency were significantly lower than those of the virus-free plants under Zn sufficiency. The Pn, Tr, and Gs in the leaves of plants infected with GFabV under Zn deficiency decreased to 16.27%, 20.08% and 21.99% of that in the leaves of the virus-free plants under Zn sufficiency, respectively. Transcriptome sequencing and RT-qPCR results showed that the expression levels of PsbP, petC, PSBO, and psaD in the leaves infected with GFabV under Zn deficiency decreased to 41.50%, 54.81%, 41.04% and 44.45%, respectively, compared with those of the virus-free plants under Zn sufficiency. The expression levels of ATPD, SEND33, and psbA in the leaves were significantly decreased under Zn sufficiency. The expression levels of PPD4 and psbA in the leaves of virus-free plants were significantly decreased under Zn deficiency. The expression levels of PsbP, PSBO, and psaD in leaves infected with GFabV under Zn deficiency decreased to 55.03%, 43.26% and 53.36%, respectively, compared with those of the leaves infected with GFabV under Zn sufficiency.【Conclusion】The chlorophyll content of ‘Shine Muscat’ grapevine leaves carrying GFabV was significantly reduced, and the expression level of GFabV was increased under Zn deficiency. The leaves showed shrinkage leaflets and slight chlorosis symptoms. GFabV down-regulated photosynthesis-related genes expression such as PsbP, PSBO, and psaD, resulting in a significant decrease in photosynthetic parameters and chlorophyll fluorescence parameters in leaves, which affected the photosynthetic efficiency of leaves.

【Objective】Soil organic carbon pool activity and stability are important indicators that directly reflect soil quality. This study aimed to explore the effects of long-term crop rotation system on soil organic carbon, active organic carbon and soil carbon pool management index, so as to provide the scientific management of soil carbon pool and rational crop layout in black soil areas.【Method】The experiment started in 2016, and 7 treatments were set up: potato continuous cropping (P-P), maize continuous cropping (M-M), soybean continuous cropping (S-S), soybean-maize rotation (S-M), soybean-potato rotation (S-P), maize-maize- potato rotation (M-M-P), and soybean-maize-potato rotation (S-M-P). P-P was used as a control. The characteristics of soil organic carbon (SOC), readily oxidizable carbon(ROC), inert organic carbon (IOC) and soil carbon pool management index (CPMI) in 0-60 cm soil layer at the harvest stage in 2022 and 2023 were analyzed systematically.【Result】Compared with the P-P treatment, in 2022 and 2023: (1) SOC content under S-M-P and S-M treatment in 0-10 cm soil layer increased significantly by 10.22%-12.49% and 20.67%-36.75%, respectively. The M-M-P treatment of 10-20 cm soil layer significantly increased by 16.65% and 33.76%, respectively. SOC content under S-M-P and M-M-P treatments in 20-40 cm soil layer was significantly increased by 28.74%-36.78% and 48.78%-53.67%, respectively. In 2023, the S-M-P in 40-60 cm soil layer was significantly increased by 14.90% (P<0.05). (2) ROC₃₃₃ content in 0-10 cm soil layer under S-M and M-M-P treatment was significantly increased by 20.09%-20.41% and 34.94%-39.69%, respectively. ROC₃₃₃ of all rotation treatments in 10-20 cm soil layer increased significantly by 13.16%-26.32% and 28.98%-52.63%, respectively (P<0.05). (3) ROC₁₆₇ content in S-P, S-M and S-M-P treatments in 0-10 cm soil layer was significantly increased by 21.11%-35.46% and 42.33%-44.85%, respectively (P<0.05). (4) ROC_33.3 content in 0-10 cm soil layer under S-M-P treatment was significantly increased by 18.04% and 19.02%, respectively (P<0.05). (5) IOC of S-M-P treatment in 0-10 cm soil layer was significantly increased by 13.30% and 14.84%; M-M-P, S-M-P and S-M treatments in 20-40 cm soil layer significantly increased by 20.38%-52.51% and 59.56%-69.54%, respectively (P<0.05). (6) CPMI in 0-10 cm soil layer was significantly increased by 24.07%-28.13% and 41.46%-42.57% under S-M and M-M-P treatments, respectively. All rotation treatments in 10-20 cm soil layer were significantly increased by 17.34%-31.49% and 36.97%-61.11%, respectively (P<0.05). 【Conclusion】In conclusion, maize-soybean, soy-maize-potato and maize-maize-potato rotation treatments were beneficial to improve soil carbon pool activity and increase soil carbon stability. Leguminous crop rotation could not only increase the activity of organic carbon pool but also maintain its stability, which was conducive to the stability of soil carbon pool balance in black soil.

【Objective】This study aimed to establish an one-time side-deep application technology of slow/controlled-release nitrogen (N) fertilizer with high yield, high-N efficiency and low-carbon emission, so as to provide a new way for green and simplified ecological cultivation of rice in the middle and lower reaches of the Yangtze River. 【Method】The late-maturing medium japonica rice of Nanjing 9108 and Taixiangjing 1402 with high-yield, high-quality and similar growth period were selected in this study. The controlled-release N fertilizer with resin-coated urea (N 43%, the hydrostatic controlled-release cycle was 100 d) and common urea (46% N) were used as N fertilizer. Five different application ratios of controlled-release N fertilizer rate to common urea rate were set for different treatments of 100%﹕0 (S1), 80%﹕20% (S2), 60%﹕40% (S3), 50%﹕50% (S4) and 40%﹕60% (S5). The N fertilizer as base fertilizer was applied using the one-time side-deep application. Conventional N fertilization (CK) and no N fertilization (0N) control treatments were also included. The effect of different treatments on rice yield, N absorption and utilization efficiency, and greenhouse gas emissions were investigated. 【Result】(1) Compared with CK treatment, the rice yield under S1 treatment was significantly reduced, S2 treatment had no significant difference, S3 and S4 treatments were significantly increased, and S4 treatment was significantly higher than S3 treatment. The yield of Nanjing 9108 under S3 and S4 treatments increased by 2.2%-3.2% and 3.6%-5.4% than that under CK, respectively, while the yield of Taixiangjing 1402 under S3 and S4 treatments increased by 0.9%-3.4% and 3.1%-5.0%, respectively. The most important thing was that there was a consistent law between years and varieties. (2) Compared with CK treatment, the N uptake under S1-S5 treatments decreased significantly at tillering stage and jointing stage (except S4 treatment), but it increased significantly at heading stage and maturity stage (except S1 treatment). The N accumulation under S1-S5 treatments at seeding-tillering stage. However, it increased significantly at tillering-jointing stage and jointing-heading stage decreased significantly compared with CK treatment. Finally, the N agronomic efficiency, N uptake efficiency, and N partial factor productivity under S1-S5 treatments were significantly higher than that under CK (except S1 treatment); among them, that of Nanjing 9108 decreased by 3.0%-14.7%, 11.6%-23.2%, and 0.4%-3.7%, respectively, and Taixiangjing 1402 decreased by 2.3%-14.8%, 11.3%-24.6%, and 0.8%-5.0%, respectively. The increase under S4 treatment was the largest, followed by S3. (3) Compared with CK treatment, the accumulation of CH₄ emissions of S1-S5 treatments at tillering-jointing stage, heading-maturity stage, and the whole growth period decreased significantly. Among them, Nanjing 9108 decreased by 48.0%-64.1%, 55.1%-68.7%, and 26.8%-35.6, respectively, and Taixiangjing 1402 decreased by 42.4%-49.2%, 46.4%-61.9%, and 24.9%-37.5%, respectively. The increase under S4 treatment was the largest, followed by S3. The accumulation of N₂O emissions of S1-S5 treatments at transplanting-tillering stage, tillering-jointing stage, and the whole growth period decreased significantly compared with CK treatment. Among them, Nanjing 9108 decreased by 42.9%-60.8%, 40.8%-73.0%, and 33.9%-58.9%, respectively, and Taixiangjing 1402 decreased by 24.5%-53.3%, 39.5%-57.6%, and 29.9%-30.7%, respectively. The increase under S5 treatment was the largest. Finally, the GWP (Global Warming Potential) and GHGI (Greenhouse Gas Emission Intensity) of S1-S5 treatments decreased significantly compared with CK treatment, among which Nanjing 9108 decreased by 26.7%-35.3% and 25.3%-37.9%, respectively, and Taixiangjing decreased by 26.6%-37.9% and 28.1%-40.4%, respectively. The largest decrease was under S3 treatment, followed by S4 treatment. 【Conclusion】The combined application ratios of slow/controlled-release N fertilizer to common urea was 50%-60%:50%-40% at one-time with using the side-deep application, which had better high-yield, high-N efficiency and low-carbon emission outcome. It could be used as a light and simplified N application technology for high-yield, high-efficiency, green and low-carbon rice in the middle and lower reaches of the Yangtze River.

【Objective】The combination of manure and chemical fertilizers can enhance crop yield and soil fertility, yet the release rates of nitrogen and phosphorus in manure fertilizer under chemical fertilization and their influencing factors remain unclear. Therefore, it was of great significance to clarify the manure nutrient release rate to improve nutrient use efficiency and scientifically manage manure nutrients. 【Method】This study utilized a long-term field experiment (established in 2013) on sandy loam fluvo-aquic soil, adopting a randomized block design with five treatments: no reduction in fertilizer (F_-0%, N-P₂O₅-K₂O=210-120-60), no reduction in chemical fertilizer with manure fertilizer (MF_-0%), and 20%, 30%, and 40% reduction in chemical fertilizer with manure fertilizer (MF_-20%, MF_-30%, and MF_-40%). At wheat maturity, yield and soil nutrient indicators were measured, and organic manure nitrogen (N) and phosphorus (P) release rate and their influencing factors were analyzed. 【Result】Among four combined application of manure fertilizer and chemical fertilizer treatments, MF_-30% achieved optimal wheat yield improvement and fertilizer reduction. Under the MF_-30% treatment, the yields in 2023, 2024, and the average of the two years were 8.6, 8.6, and 8.6 t·hm^-2, respectively, representing increases of 0.3, 0.1, and 0.1 t·hm^-2 compared with the F_-0% (no reduction in chemical fertilizer) treatment. Simultaneously, MF_-30% significantly increased soil organic carbon, easily oxidized organic carbon, mineral nitrogen, available phosphorus, microbial biomass carbon, and microbial biomass phosphorus (P<0.05). The release rate of nitrogen and phosphorus in manure fertilizers decreased with increasing chemical fertilizers inputs. The nitrogen release ranged from 11.1% to 60.7% (mean 37.7%), while phosphorus release ranged from 8.3% to 54.4% (mean 30.4%). PLS-PM model analysis showed that exogenous fertilizer input (C, N) and soil nutrients (easily oxidized organic carbon, mineral nitrogen) had direct and highly significant positive effects on nitrogen release (P<0.01), with effect values of 3.054 and 1.230, respectively. Exogenous fertilizer stoichiometric ratios (C/N, C/P) exerted direct and highly significant negative effects on nitrogen release (P<0.01), with an effect value of -1.377. Exogenous fertilizer input (N, P) and stoichiometric ratio (N/P, C/P) showed direct and significant negative effects on phosphorus release (P<0.05), with effect values of -1.758 and -0.640, respectively. 【Conclusion】In fluvo-aquic soil, the average release rate of nitrogen and phosphorus in manure fertilizer were 37.7% and 30.4%, respectively. Both N and P release rates declined with increasing chemical fertilizer inputs, and exogenous fertilizer inputs and their stoichiometric ratios directly and significantly affected manure nutrient release rates.

【Objective】The aim of this study is to clarify the effects of different soil moisture conditions (quantified by soil water content) on navel orange fruit growth, yield and quality in the southern red soil hilly area, and to provide a theoretical basis for the establishment of a regulated deficit irrigation system for the high-quality and high-efficiency production of navel oranges in Gannan.【Method】Using 6-year-old Newhall navel oranges in Gannan as test material, four water treatment gradients were defined based on different percentages of field capacity (θ_f): regulated deficit irrigation L (75%-85% θ_f ), M (65%-75% θ_f ), S (60%-70% θ_f ), and full irrigation FI (>85% θ_f). The effects of different soil moisture conditions on fruit expansion and color change process, fruit yield, water use efficiency and different quality indicators were analyzed during two key growth stages: the fruit expansion stage (stage III) and the color transition and ripening stage (stage IV). A comprehensive evaluation system for fruit quality was constructed using principal component analysis (PCA) to conduct quantitative scoring and ranking of each treatment.【Result】During stage III, the fruits grew rapidly. Regulated deficit irrigation significantly affected the fruit growth rate, with the average rate decreasing by 10.96% compared with that of FI. However, after rewatering, the III-M treatment exhibited a good compensatory effect, and its growth rate was higher than that of FI. The color transition process was slow at this stage, and there was no significant difference in the citrus color index (CCI) among all treatments. The analysis of yield and quality showed that the regulated deficit irrigation at stage III significantly improved the comprehensive quality of the fruits, but suppressed the yield. The III-S and III-M treatments had the best overall fruit quality, with significantly higher contents of total soluble solid, soluble sugars and VC, but the yields were only 57.41% and 64.19% of the highest-yield treatments, respectively. This confirmed that severe water stress at this stage was not feasible in production. During stage IV, the fruit growth rate was significantly reduced and showed an accelerated downward trend, which tended to stagnate at the end of color transition. Citrus color index (CCI) showed an accelerated increase, of which III-S, IV-L and IV-M treatments showed the most significant (P<0.05) degree of color change compared with FI, with an increase of 20.38%, 12.99% and 10.57%, respectively. The implementation of regulated deficit irrigation at stage IV resulted in a synergistic increase in yield, quality and water use efficiency. Compared with FI, IV-M treatment increased total soluble solids and soluble sugars content by 3.37% and 1.18%, respectively, and increased yield by 23.56%; IV-S treatment with severe water stress decreased total soluble solids and soluble sugars content by 5.74% and 3.15%, respectively, and decreased yield by 8.05%, confirming that there is an optimal soil water threshold for the IV stage of deficit adjustment.【Conclusion】The IV-M treatment not only achieved the highest single-plant yield of 15.05 kg and water use efficiency of 16.89 kg·m^-3, but also ranked third in comprehensive fruit quality score, establishing it as the optimal strategy for balancing high productivity and superior quality. Maintaining soil water content at >85% θ_f during the fruit expansion stage and 65%-75% θ_f during the color transition and ripening stage is identified as the optimal water management strategy for navel orange cultivation in Gannan region.

【Objective】Continuous precipitation during the harvest season results in elevated decay incidence in citrus fruits, posing a critical challenge for postharvest management. This study aimed to decipher the underlying mechanisms by which continuous precipitation compromises fruit preservation, so as to provide a theoretical basis for developing economically storage protocols. 【Method】Satsuma mandarin and Ponkan fruits were harvested under continuous precipitation during the harvest period, broad-spectrum disinfection as the control group, which subjected to three treatments: (1) industry-standard preservative cocktail (50 mg·L^-1 chlorofluoropyridine acetic acid+10 mg·L^-1 prochlorpene+100 mg·L^-1beclomethasone) (BX); (2) heat treatment (2 hours 40 ℃ ) (HT), and (3) Synergistic treatment combining BX and HT (BH). Fruits were stored under ambient conditions, with decay rates recorded weekly. Additional fruit quality parameters were also measured, including weight loss, pericarp moisture content, enzymatic activities and total phenolic/flavonoid levels. Parallel experiments were conducted on Fortunella hindsii Swingle fruits, utilizing low-field nuclear magnetic resonance (LF-NMR) to quantify bound/free water ratios. Moreover, primary metabolite profiles of the samples during storage were detected by GC-MS. 【Result】The BH treatment stabilized pericarp moisture at (75.51±1.00)%, significantly mitigating water loss relative to controls. Decay rates declined by (15.24±5.35) and 4.58 percentage points of BH-treated Satsuma mandarin and Ponkan, respectively. Moreover, BH-treated fruits exhibited elevated SOD and POD activities, maintaining phenolic/flavonoid accumulation and enhancing oxidative stress resistance. BH-treated fruit exhibited elevated SOD/POD activities, sustaining phenolic/flavonoid accumulation and enhancing oxidative stress resistance. In Fortunella hindsiii Swingle, BH reduced decay by 15.56 percentage points at day 35, with total moisture content at 69.80% (2.58% higher than controls). Furthermore, LF-NMR revealed BH promoted bound water (+2.00%) while reducing free water (-3.00%) after 28 days, inhibiting water phase migration and enhancing stability. Metabolite profiling confirmed BH-induced accumulation of resistance-related metabolites.【Conclusion】The synergistic treatment (BH) effectively maintained postharvest water homeostasis of citrus fruits harvested under continuous precipitation by increasing bound water ratios, activating ROS scavenging systems (via SOD/POD upregulation), and enhancing phenylpropanoid metabolism. Consequently, this dual regulatory mechanism of water status and metabolic networks significantly suppressed decay incidence.

【Background】The development of skeletal muscle tissue and intramuscular fat tissue directly affects beef quality, and the proliferation and differentiation of myoblasts and preadipocytes play a key role in its growth and development. Previous studies have found that Forkhead box protein O1 (FoxO1) played a transcriptional regulation role in the proliferation and differentiation of bovine myoblasts and preadipocytes, respectively, but the co-regulation mechanism in these two cells was still unclear. 【Objective】The purpose of this study was to explore the key regulatory pathways of FoxO1 in bovine myoblasts and preadipocytes, so as to provide a theoretical basis for clarifying that FoxO1 was a key genetic regulatory factor affecting beef quality. 【Method】Bovine myoblasts and preadipocytes that interfered with FoxO1 and induced differentiation for 4 days were analyzed by transcriptome sequencing, and the significantly enriched KEGG signaling pathway and significantly differentially expressed genes that FoxO1 regulated the differentiation of bovine myoblasts and preadipocytes were screened out. Small interfering RNA (siRNA) was used to inhibit the expression of FoxO1 gene in cells. Western blot (WB) was used to detect the expression level of key signal pathway marker proteins. The effects of key signaling pathways on the relative proliferation rate of bovine myoblasts and preadipocytes were detected by EdU staining. The effects of key signaling pathways on cell cycle distribution of bovine myoblasts and preadipocytes were analyzed by flow cytometry. Immunofluorescence staining was used to detect the effects of key signaling pathways on myotube formation of bovine myoblasts, and oil red O/Bodipy staining was used to detect the effect of key signaling pathways on lipid droplet formation ability of preadipocytes. The interaction between FoxO1 and target gene was verified by double luciferase reporter gene test. 【Result】A total of 11 KEGG signaling pathways and 13 differentially expressed genes were screened by transcriptome analysis, among which TGF-β signaling pathway and TGFBI gene were closely related to myogenesis and lipogenesis, and TGFBI gene was the downstream factor of TGF-β signaling pathway and directly regulated by it. WB detection results showed that interfering with FoxO1 would significantly increase the level of p-SMAD2/total SMAD2 in bovine myoblasts and preadipocytes, indicating that interfering with FoxO1 gene expression would activate TGF-β signaling pathway in bovine myoblasts and preadipocytes. Further detection confirmed that the treatment concentration of TGF-β signal pathway activator and inhibitor in bovine myoblasts and preadipocytes was 5 µmol·L^-1. EdU test showed that activating TGF-β signaling pathway would significantly reduce the relative proliferation rate of bovine myoblasts and preadipocytes (P < 0.01). The results of flow cytometry showed that activating TGF-β signaling pathway would inhibit the G1/S phase transformation of bovine myoblasts and preadipocytes. The results of myotube staining and lipid droplet staining showed that activation of TGF-β signaling pathway inhibited myotube formation of bovine myoblasts and lipid droplet formation of bovine preadipocytes. However, inhibiting TGF-β signaling pathway had the opposite effect. The double luciferase reporter gene test confirmed that FoxO1 could bind to -509—-499 bp and -490—-480 bp regions of TGFBI promoter, and up-regulate its transcription activity. 【Conclusion】FoxO1 could inhibit the proliferation and differentiation of bovine myoblasts and preadipocytes through TGF-β/SMAD-TGFBI pathway.

【Objective】This study aimed to prepare monoclonal antibodies against the pp38 protein of Marek's disease virus (MDV), to identify their antigenic epitopes, and to verify their application value.【Method】The pp38 gene was amplified using the MDV-1 GA strain as a template, and a prokaryotic expression recombinant plasmid pColdⅠ-His-pp38 was constructed. The plasmid was transformed into E. coli BL21, and the expression of the pp38-His recombinant protein was induced by IPTG and purified. The purified protein was identified by SDS-PAGE and Western blot. The purified protein was emulsified with Freund's adjuvant and used to immunize 7-week-old BALB/c mice, with immunizations repeated every two weeks. After the fifth immunization, tail blood was collected from the mice, and the serum antibody titer was detected by indirect ELISA. The mouse with the highest antibody titer was selected for a booster immunization. Three days later, splenocytes from the mouse were fused with SP2/0 cells. Positive hybridoma cell lines were screened by indirect ELISA, and after two rounds of subcloning by flow cytometry, the cells were expanded and passaged continuously for 20 generations. The stability of antibody secretion was detected by indirect ELISA. The heavy and light chain types of the antibody were identified using an antibody isotyping kit. The pp38 protein was progressively truncated and cloned into the pCAGGS-GFP vector for eukaryotic expression. Western blot was used to identify the antigenic epitope recognized by the antibody. Indirect immunofluorescence assay (IFA) was performed using chicken embryo fibroblast (CEF) cells transfected with pCAGGS-HA-pp38 and infected with MDV-1 strains (GA, Md5, 814, CVI988, and LMS), MDV-2 strain (SB-1) and HVT strain (FC126) as antigens and the antibody as the primary antibody, to detect the specificity of the antibody against exogenously and endogenously expressed pp38 proteins. Using CEF cells infected with the MDV-1 GA strain as the antigen, the antibody was used as the primary antibody to validate its application in detecting MDV by Western blot and flow cytometry.【Result】The recombinant plasmid pColdⅠ-His-pp38 was successfully constructed, and a high-purity pp38-His recombinant protein was obtained. Through mouse immunization, serum antibody titer determination, cell fusion experiments, and subcloning of cells, a monoclonal antibody 2E8 against MDV pp38 protein was prepared. The 2E8 antibody specifically recognized MDV-1 strains (GA, Md5, 814, CVI988 and LMS), and was identified as a κ-light-chain IgG1 type. The antigen recognition site was located within the amino acids 64-75 of the pp38 protein. The antibody was preliminarily validated for use in Western blot, IFA, and flow cytometry for the detection of MDV-1.【Conclusion】This study successfully expressed the MDV-1 pp38-His recombinant protein and prepared the monoclonal antibody 2E8, which specifically targeted the pp38 protein of MDV-1. The antigenic epitope was identified, and the application scope was preliminarily verified, laying the foundation for the epidemiological investigation of MDV, the study of the biological functions of the pp38 protein, and the investigation of its pathogenic mechanisms.

【Objective】Agricultural and rural modernization needs to be grounded in both general global patterns and unique Chinese characteristics. From a global perspective, investigating its evolutionary trends and influencing factors is of great significance for advancing China's comprehensive rural revitalization. 【Method】This study constructed an evaluation index system incorporating two dimensions: agricultural modernization and rural modernization. Based on the measurement of agricultural and rural development levels in 152 countries from 2000 to 2022, three-dimensional kernel density estimation and spatial Gini coefficient were employed to reveal the evolutionary trends of global agricultural and rural modernization. Furthermore, the optimal-parameter geographical detector was utilized to identify the intensity and interaction effects of socio-economic and agricultural factors. 【Result】Over the past two decades, global agricultural and rural modernization level has shown a steady upward trend. The gap between low-income and middle-income countries has been narrowing annually, yet a substantial gap with high-income countries persists. China has made remarkable progress in its agricultural and rural modernization, with its international ranking climbing from 78th to 57th. Regarding general patterns, economic development level remained a key driver. The roles of industrial structure and agricultural trade openness have become increasingly prominent. The contribution of agricultural technological progress remained important but exhibited a diminishing marginal trend, while the impact of agricultural land use structure was characterized by long-term complexity. In terms of differentiated patterns, informatization level was the primary driver for low- and lower-middle-income countries to achieve catch-up, whereas its influence diminished in upper-middle- and high-income countries. Population aging has become the dominant constraint hindering agricultural and rural modernization in middle-income countries, with a relatively minor impact on high-income countries. Environmental protection intensity showed significant differentiated effects across different income groups. The proportion of negative interaction effects between factors in low-income country groups has significantly decreased. Interaction effects among factors in lower-middle-income country groups have entirely transitioned to positive synergistic effects. Synergistic enhancement effects were prevalent among factors in upper-middle-income and high-income country groups. This indicated that the spatial-temporal differentiation of global agricultural and rural modernization was a result of the combined influence of socio-economic and agricultural factors. 【Conclusion】In advancing comprehensive rural revitalization, China should adhere to a "dual-driven" approach of concurrently promoting agricultural modernization and rural modernization. It was crucial to coordinate the relationships among economic development, social progress, and environmental protection to ultimately achieve integrated urban-rural development.