Table of Content

01 October 2025, Volume 58 Issue 19

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CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS

Screening for Soybean Host Factors that Interact with Soybean Mosaic Virus Nuclear Inclusion Proteins Using the Yeast Two-Hybrid System

YU Zhe, ZHOU FangXue, LIU RunFa, TIAN YaQi, JIHAO MuHa, WANG YongXiang, FENG WenMi, MOU KeXin, JING Yan, LI HaiYan

Scientia Agricultura Sinica. 2025, 58(19):  3799-3813.  doi:10.3864/j.issn.0578-1752.2025.19.001

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【Objective】Soybean mosaic virus (SMV) is one of the most damaging viral diseases of soybean, which seriously affects soybean yield and quality. Identification of host proteins interacting with SMV nuclear inclusion proteins (NIa-Pro and NIb) using yeast two-hybrid library screening, aiming to establish a theoretical foundation and propose novel perspectives insights into the molecular mechanisms of SMV infection and soybean resistance.【Method】Firstly, the coding sequences of NIa-Pro and NIb were cloned from the SMV strain SMV-HN and recombined into the pGBKT7 vector to construct the bait plasmids, and then soybean proteins interacting with the two viral functional proteins were identified by yeast library screening. Secondly, the host gene GmOEP16 encoding Outer Envelope Pore Protein 16 (OEP16) was cloned, and the interactions of GmOEP16 with NIa-Pro and NIb were clarified by yeast two-hybrid (Y2H) and luciferase complementation assay (LCA). Quantitative real-time PCR (qRT-PCR) was used to analyse the expression pattern of GmOEP16 under SMV treatment and exogenous hormone induction. Finally, virus-induced gene silencing (VIGS) was used to validate the function of GmOEP16 gene in SMV disease response.【Result】pGBKT7-NIa-Pro and pGBKT7-NIb recombinant plasmids were successfully constructed, and 12 soybean host proteins were screened for interactions with NIa-Pro and NIb, respectively. The Y2H assay was further used to verify that NIa-Pro interacted with GmOEP16 and GmDEG5, and NIb interacted with GmOEP16, GmZC3H18 and GmAHP1. The LCA assay was further used to clarify that GmOEP16 interacted with both NIa-Pro and NIb. Expression analysis revealed that GmOEP16 was induced by SMV infection and responded rapidly to salicylic acid (SA) and abscisic acid (ABA) stimuli during early response. The VIGS assay showed that effectively silencing of GmOEP16 resulted in no obvious susceptibility phenotype in leaf tissues relative to the wild-type controls. Meanwhile, the expression of SMV-CP was significantly reduced in the GmOEP16-silenced plants, suggesting that the soybean resistance to SMV was enhanced. Collectively, these findings demonstrated that GmOEP16 could function as a negative regulator of SMV resistance in soybean.【Conclusion】The pGBKT7-NIa-Pro and pGBKT7-NIb bait vectors were successfully constructed, and each 12 soybean host proteins that respectively interacted with pGBKT7-NIa-Pro and pGBKT7-NIb were identified. Among them, GmOEP16 interacted with both NIa-Pro and NIb. GmOEP16 responded to SMV induction and negatively regulated SMV resistance, which promoted SMV infection on soybeans.

Characterization of Antioxidant Activities in Sesame Leaves and Screening of High Antioxidant Germplasm

LUO ZiShu, ZHANG YiJia, ZHOU Rong, ZHANG YanXin, ZHOU Ting, YOU Jun, WANG LinHai

Scientia Agricultura Sinica. 2025, 58(19):  3814-3824.  doi:10.3864/j.issn.0578-1752.2025.19.002

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【Objective】Flavonoids and polyphenols are the main natural antioxidant active components in plants, which are abundant in sesame leaves. Analyzing the contents of antioxidant active components such as total flavonoids and total polyphenols in sesame leaves at different growth stages and positions, as well as the changes in antioxidant activities, and screening sesame germplasm with high antioxidant active components in leaves, will provide theoretical basis and excellent materials for the development and utilization of sesame leaves.【Method】The extraction process of total flavonoids and total polyphenols from leaves was optimized by a one-way test, and total flavonoids, total polyphenols, and antioxidant activity (DPPH scavenging ratio) were determined in sesame leaves at different growth stages and leaf positions, as well as leaves of 154 sesame germplasm.【Result】The optimal conditions for the extraction of total flavonoids and total polyphenols from the leaves were: 80% ethanol as the extraction solvent, solid-liquid ratio of 1:50 (g·mL^-1), oscillation time of 4 min, oscillation frequency of 1 250 r/min and ultrasonic time of 35 min. With the process of sesame growth and development, the total flavonoid content of sesame leaves increased rapidly from the initial-bloom stage to the full-bloom stage, and reached the peak at the mature stage. The total polyphenols content generally showed a continuous increasing trend, slightly decreased at the final flowering period, but the difference was not significant. The antioxidant activity generally shows a continuous increasing trend. At mature stage, the total flavonoid content and antioxidant activity in leaves at different leaf positions showed a gradient distribution of middle > lower > upper, while the total polyphenols showed upper > middle > lower. The total flavonoid content in the leaves of 154 sesame germplasm ranged from 20.94 to 57.43 mg CAE·g^-1, the total polyphenol content ranged from 16.04 to 65.75 mg GAE·g^-1, and the antioxidant activity ranged from 54.09% to 80.45%. Cluster analysis divided 154 materials into four groups, group Ⅰ materials had relatively high total flavonoid and total polyphenol contents and the three indexes were relatively balanced; group Ⅱ had high values of antioxidant activity; group Ⅲ had mostly median levels of total flavonoid and total polyphenol contents and low antioxidant activity; and group Ⅳ had low values of overall antioxidant indexes. Five excellent leaf germplasm with outstanding antioxidant activity indexes were screened: Sesame in Xinjiang E’min, White Sesame in Shaanxi Weinan, White Sesame in Shaanxi Baoji, 68·544 in Nicaragua and K2 in Guinea, respectively.【Conclusion】The differences in antioxidant activity indexes of sesame leaves at different growth stages and different leaf positions were systematically revealed. Sesame leaves harvested from the middle position at mature stage had the highest content of antioxidant substances and antioxidant activity.

Evaluation of 111 Alfalfa Germplasm Resources for Seedling Phenotypic Drought Tolerance Characterization

BAO MingFang, QIN Yan, CHEN CaiJin, ZHANG ShangPei, ZHANG GuoHui, SHA XiaoDi

Scientia Agricultura Sinica. 2025, 58(19):  3825-3836.  doi:10.3864/j.issn.0578-1752.2025.19.003

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【Objective】To explore the ideal traits and methods that can characterize the drought resistance of the core germplasm population of alfalfa at the seedling stage, and to mine excellent drought-resistant germplasm, so as to provide technical support and material basis for the identification of drought resistance of alfalfa at the seedling stage, germplasm innovation and breeding.【Method】Using 111 core germplasms of alfalfa as materials, the single drought resistance coefficients of six traits, namely plant height (PH), shoot fresh weight (SFW), shoot dry weight (SDW), main root length (MRL), root fresh weight (RFW), and root dry weight (RDW), were determined under natural drought stress and normal water supply (control). Combining the analysis methods such as the single drought resistance coefficient, correlation, principal component, membership function, linear stepwise regression, and clustering of each trait of alfalfa, the response differences of each alfalfa germplasm to drought stress were evaluated, the traits and methods for identifying drought resistance at the seedling stage were screened, and the excellent resources of drought resistance at the seedling stage of alfalfa were explored.【Result】The analysis of the single drought resistance coefficient indicated that drought stress significantly inhibited all six traits of alfalfa at the seedling stage. The results of trait correlation showed that there was a positive correlation among the six traits. The principal component results indicated that the six individual drought-resistant traits of alfalfa could be combined into four comprehensive drought-resistant traits, and the cumulative contribution rate reached 86.885%. The methods such as single drought resistance coefficient, correlation, principal component and linear stepwise regression were comprehensively evaluated to determine that SFW, SDW, RFW and RDW were the ideal traits for evaluating alfalfa materials at the seedling stage. Using the classification methods of CDC value and D value, the drought resistance of 111 core germplasm populations of alfalfa at the seedling stage was classified. It was found that there were only subtle differences in the classification of drought resistance of various germplasm by the two drought resistance classification methods. The D values of 111 alfalfa core germplasms were clustered and classified. The various germplasms were divided into 5 categories, which belonged to strongly drought-resistant, moderately drought-resistant, moderately drought-resistant and drought-sensitive germplasms respectively.【Conclusion】Determine that SFW, SDW, RFW and RDW are the best traits for drought resistance evaluation of alfalfa at the seedling stage; The number of highly drought-resistant and relatively drought-resistant materials of alfalfa at the seedling stage excavated was 6 and 25 respectively.

TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY

Impact of Post-Anthesis Heat Stress on Nitrogen Use Efficiency and Yield Components in Wheat

LEI BiXin, YU YongBo, ZHANG MingTong, CUI GuoJi, HONG JiaWen, HU Tao, YOU AiXin, ZHANG WenJing, MA ShangYu, HUANG ZhengLai, FAN YongHui

Scientia Agricultura Sinica. 2025, 58(19):  3837-3856.  doi:10.3864/j.issn.0578-1752.2025.19.004

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【Objective】This study aimed to investigate the impact of post-anthesis heat stress on yield formation and nitrogen assimilation capacity in wheat genotypes differing in heat tolerance, so as to provide a theoretical foundation for resilient and stable-yielding cultivation strategies.【Method】Field experiments were conducted from 2022 to 2024 at the National High-Tech Agricultural Park of Anhui Agricultural University using a split-plot design. Temperature was set as the main factor with two levels, including high temperature stress (HT) and ambient control (CK), while three nitrogen rates (no nitrogen (N0), 112.5 kg·hm^-2 (N1), and 225.0 kg·hm^-2 (N2)) and six wheat cultivars (three heat-tolerant: HM33, LK1109, AN1589; three heat-sensitive: FM5, TN19, WK1702) were arranged as subplot factors. High temperature stress was applied after anthesis. Grain yield, photosynthetic parameters (LI-6800), and activities of key nitrogen metabolism enzymes (spectrophotometry) were determined.【Result】High-temperature stress after anthesis significantly inhibited wheat growth, development, and physiological metabolism, leading to a marked decrease in yield, dry matter weight, relative chlorophyll content (SPAD), leaf area index (LAI), net photosynthetic rate (P_n), stomatal conductance (G_s), transpiration rate (T_r), nitrate reductase (NR) activity, and glutamine synthetase (GS) activity, as well as nitrogen accumulation, nitrogen use efficiency, nitrogen absorption efficiency, and nitrogen fertilizer use efficiency. The yield reduction due to high-temperature stress exhibited significant varietal heat tolerance differences and nitrogen application effects: the two-year average yield reduction of heat-tolerant varieties of HM33, LK1109, and AN1589 under N0, N1, and N2 treatments were 9.71%-6.13%, 9.91%-6.24%, and 11.87%-6.42%, respectively, lower than the reductions in sensitive varieties of FM5, TN19, and WK1702, which were 15.26%-10.38%, 12.56%-9.84%, and 12.93%-11.17%, respectively. In terms of physiological mechanisms, high-temperature stress after anthesis significantly reduced P_n across all nitrogen treatments, with the reduction showing a decreasing gradient as nitrogen levels increased: N0>N1>N2. The changes in G_s and T_r followed the same pattern as P_n. Furthermore, high-temperature stress significantly reduced NR and GS activity in the flag leaves across all nitrogen treatments, but increased nitrogen fertilization effectively and alleviated the decline in enzyme activity, with the highest enzyme activity observed under the N2 treatment. The reduction in nitrogen use efficiency under high-temperature stress also showed varietal differences: the nitrogen use efficiency of the heat-tolerant variety HM33 decreased the least under the N2 treatment (by 20.00%), while the sensitive variety FM5 exhibited the greatest decrease (31.55%) under the same treatment.【Conclusion】Post-flowering high temperature stress significantly reduced wheat yield, while the application of nitrogen fertilizers (112.5 and 225.0 kg·hm^-2) effectively mitigated this decline. Heat-tolerant varieties minimized yield losses by maintaining the activity of key nitrogen-metabolizing enzymes and optimizing nitrogen assimilation and transport. Increased nitrogen application, particularly at the 225.0 kg·hm^-2, significantly enhanced nitrogen use efficiency and promoted the accumulation of assimilates in grains. These results demonstrated that combining heat-tolerant genotypes with appropriate nitrogen management could improve thermotolerance in wheat, which provided a theoretical foundation for cultivating high and stable yields under heat stress.

Comprehensive Assessment of Wheat Seedling Growth Status Based on Multimodal Data

SHAO MingChao, AN JingWei, LIU BoRui, WU JianShuang, ZHANG Qi, YAO Xia, CHENG Tao, JIANG ChongYa, CAO WeiXing, ZHENG HengBiao, ZHU Yan

Scientia Agricultura Sinica. 2025, 58(19):  3857-3871.  doi:10.3864/j.issn.0578-1752.2025.19.005

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【Objective】The seedling condition of wheat reflects the growth status and health level of the seedlings, which is an important basis for yield prediction and field management. Traditional seedling condition evaluation methods relying on manual expertise have limitations in large-scale field applications, such as low efficiency, strong subjectivity, and difficulty in generalization. This study used UAVs equipped with RGB sensors, combined with ground-measured agronomic parameters, to explore a comprehensive wheat seedling condition assessment method that integrated multimodal remote sensing features, so as to provide a technical pathway for large-scale and cross-regional monitoring.【Method】Multi-site and multi-altitude UAV flight tests were designed in Jiangsu Province to capture UAV imagery and to simultaneously collect agronomic parameters, such as tiller number and canopy coverage. Based on vegetation indices and texture features, crop spectral and structural information was extracted. Feature selection was performed using Information Value (IV) and GINI coefficients. Various machine learning models, including random forest (RF), extreme gradient boosting (XGBoost), and gradient boosting decision tree (GBDT), were developed to assess the classification accuracy of seedling condition. The optimal image resolution was determined based on the local variance coefficient to enhance the stability and cross-regional adaptability of the application.【Result】The enhanced green-red difference index (EXGR) showed the best accuracy in identifying canopy coverage during the seedling stage (Pixel Accuracy (PA)=0.69, Specificity (S)=0.83). The green-red ratio index (GRRI) exhibited a significant correlation with tiller number (R²=0.58, relative root mean square error (rRMSE)=0.28). The Random Forest algorithm, which integrates agronomic parameters and remote sensing features, achieved the highest accuracy in seedling condition grade classification (PA=0.85, R=0.86). Tiller number and texture information (E_energy) contributed the most to the seedling condition grade classification (IV>0.70). A flight altitude of (35±5) m was found to be an important reference for obtaining high-quality UAV data (local variance=0.17).【Conclusion】This study constructed a comprehensive wheat seedling condition assessment framework integrating agronomic parameters and remote sensing features, which demonstrated the feasibility and efficiency of portable UAV RGB imagery combined with machine learning methods for cross-regional seedling condition grade monitoring. This method could provide data support and methodological references for regional-scale dynamic seedling condition assessment, crop management strategy formulation, and food security assurance.

Response of Maize Photosynthetic Production Capacity in Saline- Alkaline Soil to Organic Fertilizer Application Rates Under Differential Tillage Practices

LI YueQi, MA ZhongHua, SU Ming, LIU Hao, MA FengLan, MA XiaoYing, LI Tao, LI QingYun, ZHANG Dan, LIU JiLi, WU Na

Scientia Agricultura Sinica. 2025, 58(19):  3872-3889.  doi:10.3864/j.issn.0578-1752.2025.19.006

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【Objective】Aiming at the problems of soil degradation and crop productivity limitation in saline-alkaline land in the Yinhuang Irrigation Area of Ningxia, this study aimed to investigate the effects of vertical deep rotary tillage with organic fertilizer on the production capacity of maize (Zea mays L.) in terms of photosynthesis material, so as to provide the theoretical basis for maize production in saline-alkaline land in the area.【Method】This study was conducted in Pingluo, Ningxia, China, in 2021-2022. The maize cultivar Xianyu 1225 was used as the test material, and a split-zone experimental design was adopted, with the main zone being the tillage method (DT, vertical deep rotary tillage; TF, conventional tillage), and the subzones being the organic fertilizer dosage (M0, no fertilization; M1, 0.75×10⁴ kg·hm^-2; M2, 1.50×10⁴ kg·hm^-2; M3, 2.25×10⁴ kg·hm^-2). The photosynthesis and fluorescence parameters of maize leaves, dry matter accumulation and transport as well as the composition of maize yields at the maturity stage were measured at 10, 25, 60, 75, 95, and 120 d after seedling emergence, and the changes in the indexes of maize photosynthetic material production in the presence of the interactions between different tillage and organic fertilizer were analyzed, and then the effects of the tillage-fertilizer measures on the dry matter production of maize in saline and alkaline land were investigated.【Result】(1) Compared with TF combined with M2, DT combined with M2 significantly increased the leaf area index (LAI) and photosynthetic potential (LAD), as well as photosynthetic and fluorescence parameters. Specifically, it enhanced: net photosynthetic rate (P_n) by 8.4%-35.0%, stomatal conductance (G_s) by 7.7%-19.8%, maximum photochemical efficiency of PSII (F_v/F_m) by 7.7%-17.1%, and potential maximum photosynthetic capacity of PSII (F_v/F_o) by 10.0%-30.3%. (2) DT combined with M2 significantly increased the maximum DMA rate (G_max) and mean DMA rate (G_mean), while optimally controlling the time to reach G_max (T_max) and active duration of DMA (D). It also enhanced the contribution rate of post-anthesis DMA to grain yield, which was conducive to high yield formation. (3) Correlation and principal component analysis (PCA) revealed that maize yield and G_mean showed significant or highly significant positive correlations with LAD, P_n, G_s, F_v/F_m and ABS/RC. Furthermore, the comprehensive PCA scores for organic fertilizer rates under both tillage practices consistently ranked as M2>M3>M1>M0.【Conclusion】Vertical deep rotary tillage combined with organic fertilizer at 1.50×10⁴ kg·hm^-2 (DT+M2) effectively enhanced LAI and LAD in maize grown on saline-alkali soil, optimized its photosynthetic and fluorescence characteristics, and significantly improved dry matter accumulation and translocation traits, thereby promoting crop yield. This treatment was recommended as a saline-alkali soil improvement measure for the Ningxia Yellow River Irrigation District.

PLANT PROTECTION

Molecular Characterization and Evolutionary Dynamics of Tomato Leaf Curl New Delhi Virus Isolate from Wax Gourd (Benincasa hispida) in Guangdong

GUO MengZe, ZHANG Lei, SUN PingPing, JIANG Biao, YAN JinQiang, LI ZhengNan

Scientia Agricultura Sinica. 2025, 58(19):  3890-3904.  doi:10.3864/j.issn.0578-1752.2025.19.007

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【Objective】Tomato leaf curl New Delhi virus (ToLCNDV) is one of the most severe viral pathogens affecting cucurbit crops in recent years. Reports on the genome sequences of ToLCNDV isolates from China remain limited. ToLCNDV infection in wax gourd (Benincasa hispida) has not been reported in China. The objective of this study is to investigate the occurrence patterns of ToLCNDV in B. hispida in Guangdong Province, analyze sequence characteristics, pathogenicity, genetic diversity, and spatiotemporal dynamics of ToLCNDV isolates from China, and to provide a theoretical basis for the prevention and control of ToLCNDV.【Method】The complete genome of ToLCNDV was amplified using high-throughput sequencing and PCR. PCR assays were performed to detect ToLCNDV in 79 B. hispida samples. The obtained full-length genome sequences were subjected to phylogenetic analysis, sequence identity assessment, genetic diversity evaluation, Bayesian phylogenetics, and phylogeographic analysis. Pathogenicity was tested on 12 potential host species using mechanical sap-inoculation.【Result】High-throughput sequencing revealed that ToLCNDV was present in the collected B. hispida samples. PCR assays confirmed ToLCNDV infection in 58 of 79 suspected virus samples, representing a detection rate of 73.4%. The B. hispida isolate of ToLCNDV was mechanically transmissible through sap-inoculation to eight plant species. These included Citrullus lanatus, Luffa aegyptiaca, Cucurbita pepo, Phaseolus vulgaris, Cucumis sativus, Lagenaria siceraria, Nicotiana clevelandii, and N. benthamiana. All sap-inoculated plants developed characteristic symptoms. The complete nucleotide sequences of the DNA A and B components of the B. hispida isolate 23GD_BeHi1 were 2 739 and 2 693 bp, respectively. Pairwise sequence comparison showed 98.7%-99.7% identity for DNA A and 98.7%-99.3% for DNA B compared to representative Chinese ToLCNDV isolates. Phylogenetic trees based on complete DNA A and DNA B sequences of Chinese ToLCNDV isolates revealed two distinct clades. All isolates obtained in this study clustered within Clade I. No recombination events were detected among these isolates. Genetic diversity analyses indicated that the Chinese ToLCNDV population exhibited relatively low genetic diversity. The adequate population size remained stable, and no evidence of recombination was observed. However, significant genetic differentiation was detected between isolates from Jiangsu and Shanghai. Bayesian maximum clade credibility (MCC) trees constructed from DNA A and DNA B datasets placed Zhejiang isolates at the basal position. The estimated emergence times were April 25, 2020, for DNA A and November 30, 2020, for DNA B. Phylogeographic reconstruction suggested that Zhejiang served as the origin center of ToLCNDV in China, and the population expansion occurred in Guangdong.【Conclusion】The complete genome sequence of ToLCNDV isolate from B. hispida in China was obtained. The DNA A and B components comprise 2 739 and 2 693 bp, respectively. Mechanical sap-inoculation demonstrates that this isolate can infect C. pepo, C. lanatus, L. aegyptiaca, C. sativus, P. vulgaris, N. clevelandii, L. siceraria, and N. benthamiana. Infected plants develop leaf curling, chlorosis, and other typical symptoms.

Insecticidal Active Components and Mechanisms of Essential Oils from Illicium verum and Curcuma phaeocaulis Against Plutella xylostella

LIU HaoKai, FENG YouNa, LI Jing, LIANG Qian

Scientia Agricultura Sinica. 2025, 58(19):  3905-3918.  doi:10.3864/j.issn.0578-1752.2025.19.008

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【Objective】Elucidating the active components of Illicium verum and Curcuma phaeocaulis essential oils and their effects on enzyme activities of Plutella xylostella to provide a theoretical basis for the development of botanical insecticides against this pest.【Method】Essential oils were extracted by steam distillation, and their contact and stomach toxicities against 3rd-instar larvae of P. xylostella were determined using insect immersion and leaf-dip methods. The chemical compositions of the essential oils exhibiting promising insecticidal activity were analyzed by gas chromatography-mass spectrometry (GC-MS). The effects of cinene and zederone on the activities of acetylcholinesterase, Ca²⁺-Mg²⁺-ATPase, carboxylesterase, and catalase in P. xylostella were determined using a UV-Vis spectrophotometer.【Result】The LC₅₀ of I. verum essential oil for contact toxicity against P. xylostella on the 4th day was 54.40 μg·mL^-1, while that of C. phaeocaulis essential oil for stomach toxicity on the 4th day was 71.56 μg·mL^-1. GC-MS analysis revealed that the main components of I. verum essential oil were anethole (85.96%), estragole (6.23%), p-anisaldehyde (3.73%), and cinene (1.19%). The major constituents of C. phaeocaulis essential oil were epicurzerenone (50.64%), germacrone (14.10%), curcumenol (8.22%), furanodienone (3.99%), curzerene (2.27%), eucalyptol (1.99%), zederone (1.94%), β-elemene (1.40%), β-eudesmol (1.06%), and α-caryophyllene (1.02%). The main chemical components of I. verum essential oil, including cinene, estragole, p-anisaldehyde and anethole exhibited contact toxicity against P. xylostella with LC₅₀ values of 57.99, 205.21, 111.76, and 86.48 μg·mL^-1 on the 4th day, respectively. The major chemical constituents of C. phaeocaulis essential oil, including eucalyptol, β-elemene, α-caryophyllene, curzerene, epicurzerenone, β-eudesmol, germacrone, curcumenol, furanodienone, zederone showed stomach toxicity against P. xylostella with LC₅₀ values of 54.48, 350.93, 44.75, 376.45, 497.66, 50.94, 28.58, 7.27, 28.36, and 4.34 μg·mL^-1 on the 4th day, respectively. The stomach toxicity of zederone was stronger than that of the positive control, pyrethrin. With the increase in cinene treatment concentration, the activity of acetylcholinesterase in P. xylostella exhibited an initial inhibition, followed by recovery, subsequent reactivation, and eventual return to baseline levels. Ca²⁺-Mg²⁺-ATPase and carboxylesterase activities demonstrated sustained activation, while catalase activity showed an initial activation, followed by a period with no significant difference compared to the control. Under elevated zederone treatment concentration, acetylcholinesterase activity in P. xylostella displayed initial activation that subsequently normalized to control levels. Both Ca²⁺-Mg²⁺-ATPase and catalase maintained persistent activation throughout the experiment. Carboxylesterase activity showed a triphasic response: initial stimulation, intermediate suppression, and final reactivation.【Conclusion】The compounds demonstrating notable insecticidal activity against P. xylostella in I. verum and C. phaeocaulis essential oils were identified as cinene and zederone, respectively. These findings provide a theoretical foundation for the development and utilization of I. verum and C. phaeocaulis plant resources, as well as for the control of P. xylostella populations.

SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT

Effect of Nitrogen Application on Organic Nitrogen Mineralization Functional Genes in Rapeseed and Wheat Rhizosphere Soils Under Different Rotation Patterns

ZHAO Jian, REN Tao, FANG YaTing, YANG Xin, SHENG QianNan, LI XiaoKun, ZHU Jun, LU JianWei

Scientia Agricultura Sinica. 2025, 58(19):  3919-3931.  doi:10.3864/j.issn.0578-1752.2025.19.009

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【Objective】Soil nitrogen transformation was affected by microbial activities and modulated by crop types and fertilization practices. Understanding the effect of nitrogen application on the abundance of functional genes involved in organic nitrogen mineralization in the rhizosphere of winter crops under rice-oilseed and rice-wheat rotations, enhanced our understanding of the organic nitrogen mineralization process across different cropping systems and nitrogen fertilization regimes.【Method】A localized field experiment was conducted to collect rhizosphere soils from rapeseed and wheat in the seventh year of rice-rapeseed and rice-wheat rotation systems, under both nitrogen application and no nitrogen treatments. This analysis focused on differences in organic matter fractions and nitrogen availability. Furthermore, metagenomic sequencing was employed to analyze the abundance of functional genes mediating organic nitrogen mineralization in the rhizosphere soil.【Result】The results indicate that, compared to the no nitrogen treatment, nitrogen addition significantly increased the concentrations of potential mineralizable nitrogen (PMN), soil organic carbon (SOC), total nitrogen (TN), dissolved organic carbon/nitrogen (DOC, DON), particulate organic carbon/nitrogen (POC, PON), and mineral-associated organic carbon/nitrogen (MAOC, MAON) in rhizosphere soil. Under identical fertilization treatments, no significant differences were observed in the organic matter fractions and nitrogen availability between the rapeseed and wheat rhizosphere soils in the rice-oilseed and rice-wheat rotation systems. Compared to the no nitrogen treatment, nitrogen application reduced the abundance of functional genes encoding protease (K14645), chitinase (K01183), urease (K01429， K01430), and arginase (K01476), while increasing the abundance of functional genes encoding glutamate dehydrogenase (K00260). In the nitrogen application treatment, the abundance of functional genes encoding protease and arginase in rapeseed rhizosphere soil within the rice-oilseed rotation system was significantly higher than that in wheat rhizosphere soil within the rice-wheat rotation system. Microorganisms involved in organic nitrogen mineralization functional genes predominantly belonged to the phyla Proteobacteria, Acidobacteria, and Chloroflexi. Nitrogen addition significantly influenced the microbial community structure of protease-encoding functional genes in rhizosphere soil, whereas no significant differences were observed in the microbial community structure of organic nitrogen mineralization functional genes between rapeseed and wheat rhizosphere soils in the rice-oilseed and rice-wheat rotation systems. PMN and SOC in rhizosphere soil were identified as the primary drivers influencing the abundance of organic nitrogen mineralization functional genes and the structure of the microbial community. The abundance of functional genes encoding protease and arginase exhibited a significant negative correlation with PMN and SOC.【Conclusion】The results of this study demonstrate that both crop species and nitrogen application under different crop rotation systems can significantly influence the abundance of functional genes involved in organic nitrogen mineralization in rhizosphere soil, while also identifying the primary factors driving the abundance of these genes in rhizosphere soil.

Effects of Soybean Planting on Phosphorus Absorption of Wheat and Phosphorus Transformation in Soil

LI ShuaiBing, LI ChenXin, REN Li, YU XiaoNa, GENG SaiNan, SHENG Kai, ZHANG YinJie, WANG YiLun

Scientia Agricultura Sinica. 2025, 58(19):  3932-3945.  doi:10.3864/j.issn.0578-1752.2025.19.010

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【Objective】This study aimed to explore wheat yield, phosphorus uptake, and utilization, as well as soil phosphorus supply potential under maize-wheat and soybean-wheat rotations, so as to provide a theoretical basis for wheat planting in the North China Plain.【Method】Soybean-wheat (SW) and maize-wheat (CW) rotation field experiments were carried out in Yuanyang, Henan Province from 2023 to 2024, and three phosphorus levels application were set: no phosphorus application (P0), recommended phosphorus application (P1), and farmers' customary phosphorus application (P2), a total of 6 treatments. At the harvest period of the subsequent wheat season, plant and soil samples were collected to measure yield and yield components, nutrient accumulation, soil physicochemical properties, chemical phosphorus fractionation, phosphorus adsorption and desorption characteristics, as well as the community structure of phoD gene-harboring bacteria.【Result】Compared with maize planting, soybean planting significantly increased the grain weight and yield of wheat by 8.2%-9.4% and 10.6%-19.7%, respectively. Under different phosphorus application rates, compared with maize planting, soybean planting significantly increased wheat phosphorus accumulation and phosphorus fertilizer utilization, with an increase of 4.3%-8.3% and 31.2%-41.6%, respectively. Under different phosphorus application conditions, compared with maize planting, soybean planting increased the proportion of soil labile phosphorus (H₂O-P, NaHCO₃-Pi) and moderately labile phosphorus (NaOH-Pi), and decreased the proportion of stable phosphorus (HCl-P, residual-P). Under phosphorus application conditions, compared with maize planting, soybean planting reduced the maximum phosphorus adsorption capacity (Q_max) of the soil, increased the degree of phosphorus saturation (DPS), and promoted phosphorus desorption. Redundancy analysis showed that soil NO₃^--N, Q_max, and adsorption affinity constant (K) significantly affected the distribution of soil phosphorus forms, explaining 36.9%, 20.6%, and 10.6% of the total variance, respectively. Under the condition of phosphorus application, compared with maize planting, soybean planting significantly increased the absolute abundance of phoD gene in soil, with an increase of 17.1%-68.2%, and increased the relative abundance of Streptomyces and Actinoplanes. The complexity and connectivity of bacterial community network containing phoD gene in soil after soybean planting were higher. Further correlation analysis showed that wheat yield and phosphorus accumulation were significantly positively correlated with H₂O-P, NaHCO₃-Pi, NaOH-Pi, NaOH-Po, spike number, 1000-grain weight, and phoD abundance.【Conclusion】Soybean planting significantly enhanced the transformation of soil phosphorus (from stable to labile), reduced phosphorus adsorption and fixation, and improved microbial functional potential and interactions, thereby promoting wheat phosphorus uptake and utilization, increasing phosphorus use efficiency, and ultimately boosting wheat yield.

Carbon Footprint Assessment for the Production Cycle of Value- Added Diammonium Phosphate Containing Humic Acid

LIU RuoChen, ZHANG ShuiQin, XU Meng, XU JiuKai, YUAN Liang, GAO Qiang, LI YanTing, ZHAO BingQiang

Scientia Agricultura Sinica. 2025, 58(19):  3946-3958.  doi:10.3864/j.issn.0578-1752.2025.19.011

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【Objective】In this paper, the carbon footprint of value-added diammonium phosphate containing humic acid (DAPH) were analyzed, calculated, and evaluated in order to provide a scientific basis and theoretical support for the study on the carbon footprint of value-added fertilizers.【Method】The industrial production process of product (from "cradle" to "gate") was defined as the production cycle of product in this study, and the carbon footprint of diammonium phosphate (DAP) and DAPH products was calculated and evaluated referring to the life cycle assessment and PAS 2050 standard.【Result】(1) In terms of phosphorus nutrients (P₂O₅), the carbon footprint of DAP and DAPH production cycle was 3 636.73 kg CO₂-eq·t^-1 P₂O₅ and 3 653.16 kg CO₂-eq·t^-1 P₂O₅, respectively. The carbon footprint (in terms of P₂O₅) of DAPH was only increased by 0.45% compared with DAP. In terms of physical quantity (1 t fertilizer product), the carbon footprint of DAP and DAPH production cycle was 1 672.90 kg CO₂-eq·t^-1 and 1 660.38 kg CO₂-eq·t^-1, respectively, and the carbon footprint of DAPH (in terms of physical quantity) decreased by 0.75% compared with that of DAP. The difference of carbon footprint between DAP and DAPH was attributed to the addition amounts of humic acid synergist (HAS). (2) The carbon footprint of synthetic ammonia accounted for 67.87% and 67.57% of the carbon footprint of DAP and DAPH production cycle, respectively, which was the largest contributor for the carbon footprint of DAP and DAPH during the production cycle. However, the carbon footprint increased by adding HAS only accounted for 0.45% of the carbon footprint of DAPH.【Conclusion】Adding HAS had little effect on the carbon emissions during the DAP production, while synthetic ammonia was the biggest factor affecting the carbon footprint of DAP production cycle.

HORTICULTURE

Effects of Exogenous Zeatin on Photosynthetic Parameter, Antioxidant System and Expression of Genes Related to Zeatin Synthesis in Pepper Under Low-Temperature Combined with Low-Light Stress

ZHANG Jie, HU ChenXi, QI JianBo, ZHANG YongTai, CHEN YiBo, ZHANG YongJi

Scientia Agricultura Sinica. 2025, 58(19):  3959-3969.  doi:10.3864/j.issn.0578-1752.2025.19.012

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【Objective】The objective of this study is to explore the effects of exogenous zeatin (ZT) application at different concentrations on the tolerance and expression of ZT biosynthesis-related genes in pepper (Capsicum annuum) under low- temperature combined with low-light stress, and to reveal the mechanism of zeatin regulating the tolerance of pepper to low-temperature and low-light stress.【Method】The ‘Yangjiao No. 2’ pepper variety was used as the test material. After the seedlings had grown six true leaves, the leaves were sprayed four times with ZT solutions at concentrations of 0, 50, 100, 150, 200, and 250 μmol·L^-1. Then, the seedlings were transferred to a low-temperature combined with low-light environment simulated by an artificial climate chamber (temperature: 10 ℃/5 ℃ (day/night), light intensity: 100 μmol·m^-2·s^-1, photoperiod: 12 h/12 h (day/night)) for 7 d. Growth indices, chlorophyll content, photosynthetic parameters, chlorophyll fluorescence parameters, osmoregulatory substance levels (soluble sugars, soluble proteins, and proline), electrical conductivity (EC), reactive oxygen species (ROS) content, antioxidant enzyme activities (POD, SOD, and CAT), expression of ZT biosynthesis-related genes and endogenous ZT content were measured.【Result】Exogenous ZT application significantly enhanced plant height, stem diameter, root length, and both aboveground and underground fresh weights under stress conditions. Additionally, ZT treatment significantly increased chlorophyll content, photosynthetic parameters and chlorophyll fluorescence parameters. It also elevated the levels of osmoregulatory substances and the activities of key antioxidant enzymes, while reducing ROS accumulation. Furthermore, exogenous ZT induced the upregulation of ZT biosynthesis-related genes, including CaCKX6, CaCYP375A1, CaZOX, and CaZOG, and increased the content of endogenous ZT in pepper, which improved the low-temperature combined with low-light tolerance. Among the tested concentrations, 150 μmol·L^-1 ZT was identified as the most effective concentration.【Conclusion】Exogenous application of 150 μmol·L^-1 ZT effectively enhanced osmoregulatory substance content, stabilized chlorophyll fluorescence parameters, increased antioxidant enzyme activity, induced the upregulation of ZT biosynthesis-related genes and the production of endogenous ZT, thereby improving the resistance of pepper to low-temperature combined with low-light and alleviating the adverse impacts of low-temperature combined with low-light stress in pepper.

Effect of Fluroxypyr-Meptyl on the Quality of Orah Mandarin During On-Tree Preservation

QIN Jiaxin, OU LüSuo, XU ChenXi, ZOU YunQian, LU ChengQue, ZHU Feng, XU RangWei, CHEN XiangLing, QIN KeFeng, LI GuoGuo, CHENG YunJiang

Scientia Agricultura Sinica. 2025, 58(19):  3970-3984.  doi:10.3864/j.issn.0578-1752.2025.19.013

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【Objective】This study investigated the effects of fluroxypyr-meptyl treatment on fruit quality of Wuming Orah mandarin during on-tree preservation, aiming to provide a theoretical basis for finding alternatives to the commonly used 2, 4-D in citrus preservation, with a view to prolonging the market supply period of late-ripening citrus, and providing the technological support for high-quality development of citrus.【Method】Three treatments were applied to the stage of color change of Wuming Orah mandarin in Guangxi: water (CK), fluroxypyr-meptyl (YXZ) and 2, 4-D, with a total of three sprays at 15 d intervals. The first sampling was carried out at 20 d intervals after the last spraying, and then samples were collected every 15 days from mid-December to late March and divided into eight timepoints. The study measured the fruit's fruit drop rate and external quality, such as soluble solids, titratable acids, juice yield rate, ethanol, pyruvic acid and other physiological and biochemical fruit qualities. Additionally, metabolomics and RNA-seq analyses were also conducted, and the differential genes were verified by real-time fluorescence quantitative PCR (RT-qPCR).【Result】The fruit quality results indicated that YXZ treatment exhibited the similar effect on fruit with that of 2, 4-D. Compared with CK, the YXZ treatment group decreased the fruit drop rate by 0.81-9.76 percentage points, and increased the juice yield by 0.65%-3.56%, which could effectively maintain the internal quality of the fruit. During the on-tree preservation period, the content of ethanol, as the major off-flavor substance, was significantly decreased in YXZ treated fruits. Meanwhile, the content of pyruvic acid and the activities of ADH and PDC enzymes related to ethanol metabolism also decreased significantly. Additionally, the levels of stress-responsive primary metabolites such as proline and GABA also decreased, although the fruit quality metabolites were changed slightly. Weighted Gene Co-expression Network Analysis (WGCNA) identified nine co-expression modules, with the key module MEgreen showing significant positive correlations with ethanol levels and fruit drop (P<0.05). KEGG enrichment analysis revealed that it was mainly enriched in pathways related to glycolysis, hormone synthesis, and phenylpropanoid synthesis pathways, highlighting ethanol synthesis genes and jasmonic acid ZIM structural domain proteins from the MEgreen module. These genes’ expressions were inhibited by YXZ and 2, 4-D treatments, which was confirmed by qRT-PCR.【Conclusion】YXZ treatment effectively inhibited the expression of ADH, PDC and JAZ and reduced activity of ADH and PDC enzymes. Moreover, the treatment could decrease the ethanol and methanol content, lower the fruit drop rate, delay the reduction in juice yield, and maintain the quality of Wuming Orah mandarin while it reduced the activity of stress-responsive primary metabolites like proline. In sum, YXZ could serve as an alternative to 2, 4-D, extending the freshness period of Orah mandarin in Wuming area of Guangxi by approximately 30 days, allowing the latest harvesting period to be postponed until mid-March at the latest.

Cloning and Functional Study of AkNAC2 from Actinidia kolomikta

ZOU PeiYi, LIU MeiYan, WANG Ying, LI RanHong

Scientia Agricultura Sinica. 2025, 58(19):  3985-3999.  doi:10.3864/j.issn.0578-1752.2025.19.014

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【Objective】The NAC transcription factors constitute the largest family of transcription factors in plants, and play an important role in plant resistance to abiotic stresses such as cold. Actinidia kolomikta is one of the most cold-resistant kiwifruits. Based on the transcriptome data of Actinidia kolomikta, a NAC transcription factor family member responding to cold-AkNAC2 was obtained. The function of AkNAC2 in cold response was further studied by constructing overexpression and inhibition expression lines, which provided available gene resources for cultivating cold-resistant kiwifruit varieties.【Method】The leaves cDNA of Actinidia kolomikta were used as experimental materials to clone AkNAC2, and its sequence information and protein structure were analyzed by bioinformatics. The subcellular localization of AkNAC2 was analyzed by GFP labeling. The tissue-specific expression information of AkNAC2 was obtained by transcriptome data, and the response of AkNAC2 to cold, salt and waterlogging stress was detected by qRT-PCR. The overexpression lines of AkNAC2 Nicotiana benthamiana and the inhibitory expression lines of Actinidia kolomikta were constructed. The phenotypic, physiological and biochemical indexes and the expression of CBF pathway related genes were compared between the transgenic lines and the control after cold treatment.【Result】The CDS length of AkNAC2 is 897 bp. and has a domain. AkNAC2 encoding 298 amino acids, was a hydrophilic acidic protein, its promoter contained multiple cis-elements related to abiotic stress. Phylogenetic analysis indicated that AkNAC2 was closely related to NAC2 of Actinidia eriantha. Subcellular localization showed that AkNAC2 is localized in the nucleus. The expression level of AkNAC2 was the highest in leaves, followed by pistillate flowers, staminate flowers, fruits and stems, and the lowest in roots. The expression of AkNAC2 could be induced by cold, salt and waterlogging stress, and the response of AkNAC2 to cold stress was the most obvious. Six Nicotiana benthamiana transgenic lines were obtained by Agrobacterium-mediated, named OE1-OE6, Among them, the gene expression levels of OE2, OE4 and OE6 were higher, which were used as follow-up research materials. Under 4 ℃, compared with wild-type Nicotiana benthamiana, the relative conductivity and malondialdehyde content of the three transgenic Nicotiana benthamiana lines were lower, the content of protective soluble sugar and soluble protein significantly increased, the activity of peroxidase and superoxide dismutase increased, and the antioxidant capacity significantly increased. The expression levels of CBF pathway-related genes (NbtICE1, NbtCOR47, NbtCBF1, NbtCBF2, NbtCBF3) were significantly up-regulated. The AkNAC2 inhibitory expression lines of Actinidia kolomikta were obtained by transient transformation. qRT-PCR showed that the expression of AkNAC2 in the inhibitory expression lines was significantly lower than that in the wild type and the empty vector group. On the 4th day of treatment, the expression level reached the lowest, which was 0.40 times that of the wild type and 0.34 times that of the empty vector group. After 4 °C low temperature treatment, the relative conductivity and malondialdehyde content of the inhibited expression lines were significantly increased, the contents of protective substances such as soluble sugar and soluble protein were significantly decreased, the activities of peroxidase and superoxide dismutase were significantly decreased, and the expression levels of CBF pathway-related genes (AkCBF1.1 and AkCBF3) were significantly down-regulated.【Conclusion】A low temperature response gene AkNAC2 of Actinidia kolomikta was cloned, it may positively regulate the cold resistance of plants by affecting the expression of key genes in the CBF pathway and reducing oxidative stress.

FOOD SCIENCE AND ENGINEERING

Response of Physicochemical Properties, Edible Quality and Advanced Glycation End-Products of Stir-Fried Pork to “Huohou”

XU Ying, JI WenTong, WEI WenSong, HU XiaoJia, JIANG YuanRong, YANG Ping, ZHANG ChunHui

Scientia Agricultura Sinica. 2025, 58(19):  4000-4013.  doi:10.3864/j.issn.0578-1752.2025.19.015

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【Objective】This study aimed to create a visualization method to control the heat uniformity of pork slices during stir-frying, and to investigate the response of physicochemical properties, edible quality and advanced glycation end-products (AGEs) of stir-fried pork to “Huohou” (low-level fire and high-level fire), which could provide the theoretical support for standardizing the quality of stir-fried meat dishes and promoting the industrialized processing of traditional dishes.【Method】The heat uniformity of the meat slices in the stir-frying process was controlled based on the infrared thermal imaging system, and the changing rules of water and oil content, lipid oxidation and Maillard reaction of meat slices in stir-frying process were investigated under different “Huohou”. The edible quality of the sample was assessed by determining the color and shear force. Subsequently, the reasons for the evolution of pork tenderness were analyzed by measuring T₂ relaxation time and protein secondary structure. Finally, correlation analyses were performed to reveal the correlations of lipid oxidization and the Maillard reaction with AGEs.【Result】At the same stir-frying time, the water content and tenderness of the low-level fire group were significantly higher than those of the high-level fire group, and the oil content was significantly lower than that of the high-level fire group. During the stir-frying process, the thiobarbituric acid reactive substances (TBARS) and absorbance value at 420 nm (A₄₂₀) of the meat slices from the high-level fire group were higher than those from the low-level fire group, indicating that increasing “Huohou” accelerated the lipid oxidation and the Maillard reaction. After stir-frying for 4 min, the decrease in T₂₁ relaxation time of meat slices from the high-level fire group was 1.39 times that from the low-level fire group, which indicated that muscle contraction was intensified, and the myofibrillar distance was further reduced with the increase of “Huohou”. Compared with the low-level fire group, the high-level fire group had more ordered β-sheets transformed into random coils, suggesting that the degree of protein denaturation in the meat slices from the high-level fire group was higher than that of the low-level fire group. Meanwhile, the meat slices from high-level fire group experienced more severe contraction and protein denaturation, resulting in lower tenderness than those from low-level fire group. Combined with the results of the center temperature of the meat slices, high-level fire stir-frying took less time for samples heated to the same center temperature. High-level fire-treated meat slices experienced shorter periods of oxidation and thermal denaturation, making it easier to obtain safer and chewing-friendly meat products compared with low-level fire-treated meat slices. In addition, correlation analysis showed that lipid oxidation contributed more to the generation of AGEs than the Maillard reaction.【Conclusion】The application of infrared thermal imaging system solves the problem of limited research related to the stir-frying process caused by different degrees of doneness in the same pot. “Huohou” could be used to achieve control of the product's edible quality by regulating the water-oil migration, lipid oxidation, Maillard reaction, and protein structure of the meat slices in both time and temperature dimensions.

ANIMAL SCIENCE·VETERINARY SCIENCE

Antioxidant Physiology and Hormonal Response Pattern of Embryonic Root Mitochondria During Imbibition of Aging Seeds of Alfalfa

LI RuoHong, MA Wen, ZHAO ShiQiang, MAO PeiSheng

Scientia Agricultura Sinica. 2025, 58(19):  4014-4025.  doi:10.3864/j.issn.0578-1752.2025.19.016

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【Objective】Aging deterioration of seeds is inevitable during storage, which is mainly manifested by mitochondrial dysfunction and reactive oxygen species (ROS) accumulation. Mitochondria, as the center of cellular energy metabolism, and its ascorbic acid-glutathione (AsA-GSH) cycle are the key defense to scavenging ROS. This experiment was designed to investigate the antioxidant mechanism of the mitochondrial AsA-GSH cycle and the rules of endogenous hormones changed in the radicle during imbibition of aged alfalfa (Medicago sativa L.) seeds, and to lay a foundation for revealing the relationship between the metabolism of the radicle cells and the imbibed process in the aged alfalfa seeds.【Method】In this experiment, seed samples were treated with controlled deterioration and obtained at a medium level of alfalfa seed vigor, and unaged seeds were used as the control. After the seed germination characteristics were tested, the changes in mitochondrial antioxidant enzyme activity and antioxidant content of the radicle during imbibition (6, 12, 24 and 36 h), and the changes in hormone content of the radicle during imbibition (12, 24 and 36 h).【Result】Controlled deterioration treatment inhibited the seed germination and seedling growth, which mainly presented the decrease in seed germination potential, germination percentage and root length of seedlings. The activities of catalase (CAT), ascorbate peroxidase (APX) and monodehydroascorbate reductase (MDHAR), as well as the contents of ascorbic acid (AsA) and glutathione (GSH) were decreased in the radicle mitochondria of aged seeds within 36 h imbibition; and the activities of peroxidase (POD) and glutathione reductase (GR) increased in the radicle mitochondria of aged seeds after 24 h of imbibition. With the progress of imbibition, the difference of AsA/ oxidized ascorbic acid (DHA) and GSH/ oxidized glutathione (GSSG) ratios between aged and unaged seeds was gradually reduced. The contents of abscisic acid (ABA), gibberellin (GA₃), growth hormone (IAA) and oleuropein lactone (BR) in the radicles presented the similar tendency during the imbibition.【Conclusion】During the process of imbibition, ROS accumulated in the mitochondria of the radicle, resulting in oxidative damage and delayed seed germination. After 24 h imbibition of aged seeds, POD and GR activities in radicle mitochondria increased to maintain a certain antioxidant capacity and germination ability. It could be suggested that the enhancement of POD and GR activities would play an important role in the maintenance of seed vigor level during the imbibition of aged alfalfa seeds, which provided a basis for an in-depth exploration of the mechanism of the role of the AsA-GSH cycle in antioxidant responses, and provided a reference for optimizing the conservation strategy of forage germplasm bank and prolonging seed life.

Screening of Feed Oat Varieties and Its Evaluation of Silage Quality in Central Inner Mongolia

REN JiaHui, SUN JuanJuan, HAO YingLu, WANG FengWu, WANG JingYu, ZHANG MingWei, LI BaoHan, ZHENG ChengZhong, HE ZhuQing, WANG ZhaoLan

Scientia Agricultura Sinica. 2025, 58(19):  4026-4038.  doi:10.3864/j.issn.0578-1752.2025.19.017

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【Objective】With the continuous advancement of grass animal husbandry, there is a shortage of high-quality feed oat varieties in central Inner Mongolia, especially the lack of silage feed oat germplasm resources. Through the analysis of nutritional components and silage quality of different oat varieties, the high quality oat and silage oat varieties suitable for planting in this area were selected.【Method】In this study, 9 feed oat varieties, including Mengsi Yan No. 2, Dictator, Madison, Fuxing, Haymaker, Caesar, Tianyan No. 1, Waterfall, and Molasses, were screened. They were planted in the experimental base of the agro-pastoral ecotone of the Grassland Research Institute of the Chinese Academy of Agricultural Sciences. The yield was measured by mowing at the milk maturity stage, filling the polyethylene feed bag with silage and vacuum sealing it, storing it at room temperature for 120 days. The nutrient composition of feed oat silage before and after silage, the fermentation quality of silage and the number of microorganisms were analyzed.【Result】There were significant differences in yield, nutritional value and silage fermentation quality among different varieties of feed oats in central Inner Mongolia (P<0.05). The yield of fresh grass in the nine feed oat varieties was 40.20-59.54 t•hm^-2, and the yield of fresh grass in Mengsi Yan No. 2 was the highest (59.54 t•hm^-2), while the dry matter content of the raw materials of the nine feed oat varieties was 31.53%-41.32%, and the Fuxing (13.75%) with the highest crude protein content was 95.31% higher than that of Madison (7.04%). The content of soluble carbohydrates was low, and the highest was Molasses (4.83%). The content of neutral detergent fiber in Caesar and Fuxing was significantly lower than that of other varieties (P<0.05), and the highest content of acid detergent fiber in Dictator was 37.07%, which was significantly different from other varieties (P<0.01). After 120 days of silage, there was still a significant difference in nutrient composition between varieties (P<0.05). The dry matter content of Caesar was the highest, and the crude protein content of Fuxing was 11.98%, which was significantly higher than that of other varieties (P<0.05). The content of soluble carbohydrates in Madison was the highest, and the neutral and acidic detergent fibers of Fuxing were the lowest, which were significantly lower than those of other varieties (P<0.05). The crude ash fraction of Fuxing was 7.81%, which was significantly higher than that of other varieties (P<0.05). There were also significant differences in the fermentation quality of different varieties, with Fuxing having the lowest pH, the highest lactic acid content, no butyric acid detected, the lowest ammonia nitrogen content, and a higher number of lactic acid bacteria. According to the evaluation system of Kaiser, the Fuxing grade was 1, and the fermentation quality was the best, while the fermentation quality of other varieties was poor. The results of redundancy analysis showed that the nutritional quality of raw materials jointly explained 80.01% of the variation of silage fermentation quality. Among them, the contribution rate of crude protein was the highest, while there was a significant difference between acid detergent fiber and silage quality (P<0.01). The results of Pearson correlation showed that the nutritional quality of raw materials significantly affected the fermentation quality of silage, and crude protein, neutral and acidic detergent fiber and crude ash were the main factors affecting the fermentation quality.【Conclusion】Considering the yield, nutritional quality and fermentation quality, Fuxing could be used as a spring-sown silage feed oat variety in central Inner Mongolia.