Table of Content

01 May 2025, Volume 58 Issue 9

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CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS

Genome-Wide Association Study of Heat Tolerance at Seedling Stage in A Wheat Natural Population

LI YunLi, DIAO DengChao, LIU YaRui, SUN YuChen, MENG XiangYu, WU ChenFang, WANG Yu, WU JianHui, LI ChunLian, ZENG QingDong, HAN DeJun, ZHENG WeiJun

Scientia Agricultura Sinica. 2025, 58(9):  1663-1683.  doi:10.3864/j.issn.0578-1752.2025.09.001

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【Objective】 Wheat is a cornerstone of global food security, with its production being pivotal in both China and the international community. With global climate change, the threat of high temperature has become increasingly prominent, posing a significant challenge to wheat cultivation. The strategic identification and selection of heat-tolerant germplasm, coupled with the exploration of genes associated with heat resistance, are crucial steps. These efforts are essential for broadening the genetic diversity of heat tolerance in wheat within China, providing prerequisites for breeding heat-tolerant wheat varieties and ultimately contributing to the safeguarding of our nation’s food security in the face of a warming climate. 【Method】 In this study, a natural population of 331 wheat accessions was utilized, and artificial climate chambers were employed to simulate high temperatures conditions. The heat tolerance of wheat seedlings was assessed by monitoring their survival rate under various durations of treatment, using heat resistance grade as the evaluative metric. Meanwhile, a genome-wide association study (GWAS) was conducted using the 55K SNP chip to identify genetic loci associated with heat tolerance. Expression data from multiple tissues, including roots, leaves under heat stress were analyzed, leading to the selection of genes related to heat tolerance. Subsequently, qPCR validation of candidate genes was performed using the extremely heat-tolerant accession Xinong 889 and the heat-sensitive accession Chinese Spring (CS) as materials. 【Result】 Under high-temperature stress, significant variations in survival rates were observed among different wheat accessions. The extremely heat-tolerant, moderately heat-tolerant, moderately heat-sensitive, and extremely heat-sensitive germplasm accounted for 110, 104, 110, and 7, respectively, representing 33.23%, 31.42%, 33.23%, and 2.12% of the total. Heat-tolerant germplasms, including Xinong 889, Zhengmai 7698, Zhongmai 895, Zhoumai 18, and Fengchan 3, were identified. Through GWAS, a total of 293 SNP loci significantly associated with the 12-hour survival rates (SR) and heat resistance grades (HRG) were detected, with the phenotypic variation explained ranging from 4.40% to 12.46%. Among these, 200 loci were related to the 12-hour survival rates, and 257 were related to the heat resistance grades, with 164 loci identified as the same heat-related loci. Based on significantly associated SNP markers, 313 heat-related genes were predicted. According to gene annotation information and expression data under heat stress, 23 heat tolerance candidates were selected, and after qPCR validation of differentially expressed candidate’s genes, 20 key heat tolerance candidate genes were identified. 【Conclusion】 At the seedling stage, 331 wheat germplasms were identified for heat tolerance. A rapid method was developed for determining the survival rate of wheat seedlings subjected to treatments of varying durations at 45 ℃ to assess their heat tolerance In total, 38 heat-tolerant germplasms and 293 loci significantly associated with seedling heat tolerance were screened. Also, TraesCS1A02G355900, TraesCS1A02G389500, TraesCS5A02G550700, TraesCS5D02G557100, TraesCS6D02G402500 and TraesCS7A02G232500 represented as candidate genes were filtered out.

Development and Effectiveness Evaluation of InDel Molecular Markers Closely Linked to Fiber Strength QTL in Gossypium barbadense

LÜ Tao, SUN GuoQing, GUO DongCai, CHEN QuanJia, CAI YongSheng, FAN BiaoXing, QU YanYing, ZHENG Kai

Scientia Agricultura Sinica. 2025, 58(9):  1684-1701.  doi:10.3864/j.issn.0578-1752.2025.09.002

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【Objective】 The objective of this study is to develop InDel molecular markers for Island cotton, which is characterized by its superior fiber quality, particularly the fiber tensile strength-a key indicator of cotton fiber quality. The study aims to validate these markers using RIL (Recombinant Inbred Line) populations and resource materials, thereby providing a theoretical foundation for breeding new varieties of Island cotton with enhanced fiber quality. 【Method】 Utilizing a previously established population of 213 Pima S-7 and 5917 F_5:6 RILs, we conducted QTL (Quantitative Trait Locus) mapping to identify the locus regulating fiber strength in Island cotton, designated qFS-chr17-1. InDel markers were designed based on whole genome sequencing (WGS) data of the parental lines, followed by the identification of polymorphic markers. Preliminary validation of these markers was performed using 40 extreme family materials selected based on phenotypic data. Genotyping was carried out on both the 213 RIL population and the 213 Island cotton resource population, alongside multi-year fiber quality data to assess the markers' effectiveness. 【Result】 The genotyping of the RIL and Island cotton resource populations with the two developed InDel markers indicated a close linkage to fiber strength phenotypic data, with significant differences observed in fiber strength traits among the differentiated materials. The analysis of genotypic combinations revealed an upward trend in fiber strength across four combination types, with materials exhibiting the Hap3 (B/A) and Hap4 (B/B) genotypes demonstrating significantly greater fiber strength than those with Hap1 (A/A) and Hap2 (A/B). Furthermore, the InDel-3L2 marker showed significant correlations with fiber length, fiber uniformity, and spinning consistency index, consistent with the observed phenotypic trends. Analysis of multi-year fiber quality data from two experimental sites revealed environmental variability in fiber quality, while temperature data indicated that the developed molecular markers are minimally influenced by environmental factors. Clustering analysis of fiber quality data from 213 Island cotton resource materials, combined with molecular marker genotyping, identified eight materials exhibiting superior fiber quality. 【Conclusion】 This study successfully developed two InDel molecular markers closely linked to the fiber strength QTL (qFS-chr17-1), which maintain their effectiveness upon combination. The InDel-3L2 marker demonstrates significant correlations with fiber length, fiber uniformity, and spinning consistency index. These markers can efficiently and accurately identify high-strength fiber resources in Island cotton, contributing to the breeding of improved fiber quality. Additionally, eight materials with excellent fiber quality have been identified.

Integrated Multi-Omics Elucidates the Pigmentation Dynamics During Post-Harvest Maturation in Foxtail Millet (Setaria italica)

ZHANG YiRu, HAN Xue, YAO XinJie, FENG Jun, WEI AiLi, LI WenChao, ZHANG Bin, HAN YuanHuai, LI HongYing

Scientia Agricultura Sinica. 2025, 58(9):  1702-1718.  doi:10.3864/j.issn.0578-1752.2025.09.003

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【Objective】 The aim of the study is to investigate the variation characteristics of starch and carotenoid content in grains of the foxtail millet during post-harvest maturation, and to elucidate the molecular mechanism of this phenomenon. The study will expand new insights into carotenoid metabolism in grains, thereby providing theoretical support for the stabilization of millet color, deep processing of millet, and storage. 【Method】 The carotenoid and starch content in grains from ten varieties of foxtail millet were measured after storage for 0, 30, 60, and 90 days, respectively. Changes in starch granules of representative materials during the four storage stages were observed using confocal laser scanning microscopy. Transcriptome and proteome analyses were conducted to investigate differential genes and proteins related to starch and carotenoid metabolic pathways at different storage stages for the same material. 【Result】 Among the 10 foxtail millet varieties, the carotenoid content in the millet mainly showed an upward trend from 0 to 60 days of post-harvest maturation and began to decline after 90 days, but remained higher than that of 0 days. The starch content showed an upward trend after 30 days of post-harvest maturation and then declined overall. Microscopic observation revealed a gradual increase in carotenoid fluorescence in millet starch granules after 30 days of post-harvest maturation, with a tendency for starch plastids to convert into chromoplasts. Furthermore, the transcriptome and proteome analyses identified 1 344 differentially expressed genes (DEGs) and 224 differentially expressed proteins (DEPs), which were mainly enriched in starch degradation and carotenoid synthesis pathways. A metabolic network regulation was also constructed.【Conclusion】 During of post-harvest maturation of the foxtail millet, there is an increase trend in the carotenoid content and a decrease trend in the starch content of the millet. It is speculated that starch degradation leads to an increase in pyruvate content, which enters the plastid methylerythritol phosphate (MEP) pathway to promote carotenoid synthesis. Towards the end of post-harvest maturation of the foxtail millet, the downstream synthesis of abscisic acid is inhibited, resulting in the accumulation of substances such as beta-carotene and zeaxanthin, which subsequently affect changes in the millet color.

TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY

Multi-Angle Imaging and Machine Learning Approaches for Accurate Rice Leaf Area Estimation

WANG AiDong, LI RuiJie, FENG XiangQian, HONG WeiYuan, LI ZiQiu, ZHANG XiaoGuo, WANG DanYing, CHEN Song

Scientia Agricultura Sinica. 2025, 58(9):  1719-1734.  doi:10.3864/j.issn.0578-1752.2025.09.004

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【Objective】 Rice leaf area is a critical physiological metric that indicates photosynthetic efficiency, energy conversion, and dry matter accumulation capacity. This study aimed to develop a simple and efficient rice leaf area imaging system and prediction method, so as to provide a theoretical foundation and technical support for rapid and accurate leaf area measurement.【Method】 The study utilized representative rice varieties—Xiushui 134 (indica), Huanghuazhan (japonica), and Yongyou 1540 (indica-japonica hybrid)—as experimental materials. Leaf area data were collected from the aboveground parts during critical growth periods, and both flat-overhead-view and side-view images were captured. Using the PlantScreen high-throughput modular plant phenotyping platform, morphological and color feature information was extracted. Based on these data, various feature selection methods(Pearson correlation coefficient, maximal information coefficient (MIC), and recursive feature elimination (RFE)) combined with machine learning models (support vector regression (SVR), random forest regression (RFR), and XGBoost) and deep learning models (ResNet50, AlexNet, VGG, and SeNet) were employed to develop a simplified and efficient rice leaf area prediction model.【Result】 (1) An imaging approach that integrated flat-overhead and multi-angle side views significantly outperformed single-view methods for leaf area prediction, with R² values of 0.76-0.82 and coefficients of variation (CV) of 5.5%-13.7%, compared with R² values of 0.51-0.78 and CVs of 9.7%-27.5% for single views. The optimal system used one flat-overhead-view and one side-view image, achieving R² = 0.79, root mean square error (RMSE) = 95.3, mean absolute error (MAE) = 77.02, and CV = 6.5%. (2) Using MIC algorithm for key feature selection combined with the random forest regression model achieved excellent results (R² = 0.84, RMSE = 81.8, and MAE = 63.3), noticeably outperforming other machine learning models. The deep learning model SeNet (R² = 0.80, RMSE = 98.1, and MAE = 74.7) outperformed traditional ResNet50 and AlexNet models but showed no significant advantage over the MIC-RFR model. (3) Feature analysis indicated that the projected area and plant height from side-view images, as well as leaf perimeter and green-yellow characteristics from flat-overhead-view images, significantly contributed to leaf area prediction. The contribution of the side-view projected area (+117.4) was substantially greater than that of other features (ranging from 1.48 to 18.87).【Conclusion】 This study employed a simple and efficient leaf area prediction imaging system (one flat-overhead-view combined with one side-view image), integrated with the MIC-RFR model, to meet the high-precision and stable prediction requirements for individual rice leaf area. This method provided a powerful tool and technical support for precision agriculture and crop breeding.

The Combined Effects of 16, 17-Dihydro Gibberellin A₅ and Straw Mulching on Tillering and Grain Yield of Dryland Wheat

PU LiXia, ZHANG JiaRui, YE JianPing, HUANG XiuLan, FAN GaoQiong, YANG HongKun

Scientia Agricultura Sinica. 2025, 58(9):  1735-1748.  doi:10.3864/j.issn.0578-1752.2025.09.005

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【Objective】 Seasonal drought during winter and spring is a significant factor limiting the number of fertile spike and grain yield of wheat in Southwest China. This study investigated the combined effects of straw mulching and 16, 17-Dihydro gibberellin on tillering in wheat, spike formation, and grain yield of dryland wheat, which would enrich the theoretical framework of tillering and spike formation regulation, and provide a theoretical basis for stable and high yield of wheat in the dryland farming system. 【Method】 The experiment was conducted from 2022 to 2024 at the Renshou experimental station, which is a typical hilly dryland farming system in Southwest China. The straw mulching (SM, straw mulching with no-tillage; NSM, no straw mulching) and 16, 17-Dihydro gibberellin (DHGA₁₀₀, spraying exogenous 16, 17-Dihydro gibberellin A₅ at the three-leaf stage; DHGA₀, spraying water at the three-leaf stage)，In view of the current situation that soil drought in the hilly and dryland of Southwest China inhibits wheat tillering and spike formation, resulting in insufficient fertile spikes of wheat, the effects of straw mulching and 16, 17-Dihydro gibberellin A₅ on wheat tillering, matter accumulation and endogenous hormone content were analyzed, exploration treatments were employed to evaluated their combined effects on the tillering and grain yield of dryland wheat. 【Result】 Compared with no mulching, straw mulching increased the fertile spikes and grain yield of wheat by 13.16% and 20.64%, respectively; DHGA₁₀₀ applicated at the three-leaf stage increased the fertile spikes and grain yield of wheat by 9.7% and 14.37%, respectively, compared with no DHGA₀ application. Straw mulching combined with DHGA₁₀₀ extended the effective tillering period, promoted the occurrence of the first tiller (T1 tillers), and increased the tillering capability and tillering emerging rate of T1 tillers, ultimately increasing fertile spikes and grain yield. Compared with NSM, SM increased the tillering ability, tiller emerging rate, and fertile spikes by 46.02%, 21.21%, and 13.41%, respectively; DHGA₁₀₀ increased these parameters by 22.56%, 16.18%, and 9.72%, respectively, compared with DHGA₀. For every 0.1 increase in tillering ability per plant, the number of fertile spikes increased by 2.84%; for every 0.1 increase in tillering survival rate of tillers after stem extension, the fertile spikes increased by 19.3%; for every 10% increase in tiller emerging rate of T1 tillers, the fertile spikes increased by 14%. Both straw mulching and DHGA could regulate the endogenous hormone levels in tillers and increase the proportion of tiller dry matter to total plant dry matter. Compared with NSM, SM increased the ratios of ZR/ABA and GA₃/ABA in tillers by 52.66% and 38.68% and decreased the ratio of IAA/ABA by 11.10%. Under SM treatment, DHGA₁₀₀ increased these ratios by 14.06%, 21.67%, and 31.67%, respectively, compared with DHGA₀. 【Conclusion】 Exogenous 16, 17-Dihydro gibberellin A₅ applicated to straw mulching at the three-leaf stage promoted the occurrence and spike formation of T1 tillers via ABA/GA signaling, thereby increasing fertile spikes and grain yield of wheat. Therefore, the combination of straw mulching (8 000 kg·hm^-2) with the application of 16, 17-Dihydro gibberellin (100 mg·L^-1) at the three-leaf stage was a promising approach for high and stable grain yield of wheat in the dryland farming system.

Effects of Phosphorus Fertilizer Postpone Under Nitrogen Reduction Condition on Yield, Phosphorus Fertilizer Utilization Efficiency of Drip-Irrigated Cotton

GUO ChenLi, LIU Yang, CHEN Yan, HU Wei, WANG YouHua, ZHOU ZhiGuo, ZHAO WenQing

Scientia Agricultura Sinica. 2025, 58(9):  1749-1766.  doi:10.3864/j.issn.0578-1752.2025.09.006

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【Objective】 This study aimed to explore the regulation effect of phosphorus fertilizer postponement on the maintenance of high yield of drip-irrigated cotton under the condition of nitrogen reduction, and to define the consequence of phosphorus fertilizer postponement on the utilization efficiency of cotton phosphorus fertilizer under the condition of nitrogen reduction.【Method】 A 2-year field experiment (2022-2023) was performed in the experimental ground of Shihezi University, which used Zhongmian 109 as test material. A total of six experimental treatments were set up: conventional nitrogen application (N_ck: 400 kg·hm^-2), 50% phosphorus fertilizer management treatment at the squaring stage and 50% at the flowering and boll setting stage (total phosphorus fertilizer application rate 105 kg·hm^-2, N_ckP3), and nitrogen reduction conditions (25% nitrogen reduction, Nr: No phosphorus fertilizer was applied at 300 kg·hm^-2 (P0), 100% phosphorus was applied at the squaring stage (P1, the total application rate of phosphorus fertilizer was 105 kg·hm^-2, the same below), 75% at the squaring stage + 25% at the flowering and boll setting stage (P2), 50% each at the squaring stage and the flowering and boll setting stage (P3), 25% at the squaring stage + 75% at the flowering and boll setting stage (P4) They are respectively denoted as N_ckP3, N_rP0, N_rP1, N_rP2, N_rP3 and N_rP4.【Result】 (1) Compared with N_ckP3, only N_rP3 treatment had no significant difference in seed cotton yield; under the nitrogen reduction condition, the seed cotton yield udner other treatments increased significantly compared with P0, and the increase under P3 treatment was the largest, reaching 31.0% (mainly due to the significant increase of seed cotton yield in the middle and upper branches). (2) Compared with N_ckP3, only the N_rP3 treatment showed no significant differences in the biomass of each organ and the accumulation of phosphorus in cotton. Under reduced nitrogen, compared with P0, the postponed phosphate fertilizer increases the biomass of reproductive organs in the middle and upper fruit branches of cotton and the proportion of phosphate distribution, the increase was the greatest under the P3 treatment, which were 11.0%, 21.7% and 79.6%, 72.0% respectively, and significantly increased the biomass accumulation of cotton and promoted the phosphorus absorption and utilization. In addition, only N_rP3 treatment had a higher phosphorus utilization rate than N_ckP3, with an increase of 15.8%. (3) The yield of seed cotton and the utilization rate of phosphorus fertilizer were positive correlated with the average accumulation rate VT of aboveground and reproductive organs biomass during the rapid accumulation period. The former was also significantly positive correlated with the maximum accumulation rate Vm of reproductive organs biomass, and the latter was positive correlated with the maximum accumulation rate Vm of reproductive organs phosphorus.【Conclusion】 Under nitrogen reduction conditions, N_rP3 treatment (the proportion of the postponed phosphorus fertilizer was 50%) can enhance the transport and distribution of biomass to the reproductive organs of the middle and upper fruit branches of cotton, promote the accumulation and distribution of phosphorus from the middle and upper fruit branches to the reproductive organs, improve the utilization rate of phosphorus fertilizer, and ultimately achieved the goal of reducing nitrogen in cotton without reducing yield.

PLANT PROTECTION

Changes of Secondary Metabolites in Grapes with Different Resistance Levels in Response to White Rot Infection

TAN XiBei, LAN XuYing, LIU ChongHuai, FAN XiuCai, JIANG JianFu, SUN Lei, LI Peng, YU ShuXin, ZHANG Ying

Scientia Agricultura Sinica. 2025, 58(9):  1767-1778.  doi:10.3864/j.issn.0578-1752.2025.09.007

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【Objective】 This study aims to explore the role of secondary metabolites in grape resistance to white rot, and to identify the metabolites associated with grape resistance to white rot.【Method】 The fruits of disease resistant Vitis davidii 0941 (Vd) and the disease susceptible Vitis vinifera Manicure Finger (Vv) at color transition stage were used as experimental materials. The fruit pedicel was pricked to create a wound and inoculated with the white rot pathogen. Fruits were collected at different time points (0, 24, 48 h) after the removal of infected parts following pathogen inoculation, and a broad-targeted metabolomics approach was employed to analyze the metabolites in the resistant and susceptible varieties.【Result】 A total of 960 metabolites were detected in the metabolome, which were divided into 12 major categories, such as amino acids and their derivatives, phenolic acids, nucleotides and their derivatives, flavonoids, and lipids. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed significant differences in metabolites between the resistant variety Vd and the susceptible variety Vv before and after infection with white rot. Using |log₂ fold change|≥1 and P-value≤0.01 as the threshold for screening differential metabolites, a total of 501 differential metabolites were identified. After infection with white rot, Vd and Vv exhibited different metabolic responses, especially at 24 and 48 hours post-infection, where the number and magnitude of changes in differential metabolites were more significant in the susceptible variety. KEGG enrichment analysis showed that these differential metabolites were mainly enriched in the metabolic pathways of biosynthesis of secondary metabolites, flavone and flavonol biosynthesis, ABC transporters, ascorbate and aldarate metabolism, and biosynthesis of amino acids. WGCNA identified metabolites significantly related to disease resistance, obtaining 10 secondary metabolites that may be related to disease resistance, including one amino acid and its derivative (O-acetylserine), one phenolic acid (arbutin), one flavonoid (cyanidin-3-O-(6''-O-caffeoyl)glucoside), and seven terpenoids (α-amyrenone, botulin, 3-epiursolic acid, 2-hydroxyoleanolic acid, maslinic acid, alphitolic acid, 3,24-dihydroxy-17,21-semiacetal-12(13)oleanolic acid).【Conclusion】 This study reveals the changes in grape metabolites under white rot infection, and these secondary metabolites (amino acids and their derivatives, phenolic acids, flavonoids, and terpenoids) that are up regulated in the resistant variety V. davidi 0941 may play a significant role in the resistance to white rot.

Antibacterial Activity of Polyhexamethylene Guanidine Against Xanthomonas citri pv. citri

LIU Jie, HOU Rui, ZHOU ZeHua, YI TuYong

Scientia Agricultura Sinica. 2025, 58(9):  1779-1790.  doi:10.3864/j.issn.0578-1752.2025.09.008

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【Objective】 The objective of this study is to clarify the in vitro antibacterial activity of polyhexamethylene guanidine (PHMG) against Xanthomonas citri pv. citri (Xcc), a major agricultural pathogenic bacterium that causes citrus canker, and to evaluate the field control effect of PHMG on citrus canker.【Method】 When determining the in vitro antibacterial activity, the turbidity method was used to monitor the changes in the turbidity of the bacterial solution, so as to quantify the inhibitory degree of PHMG on the growth of Xcc. By inoculating the leaves to simulate the infection of citrus leaves by Xcc, whether PHMG could block the invasion of Xcc was observed and whether it had the effect of preventing and treating citrus canker was explored. The field experiment was carried out when the autumn new shoots were about to sprout, in an environment that was closest to the actual production problems, to test the actual effect of PHMG in preventing and treating citrus canker. Microscopic observation instruments such as scanning electron microscopy and fluorescence microscopy were used to show the surface and morphological changes of Xcc after the action of PHMG; PI staining was used to visualize the process of cell apoptosis; the crystal violet staining experiment was used to reveal the formation of biofilms of Xcc. Through these experiments, the effects of PHMG on the cells of Xcc were explored.【Result】 PHMG showed broad-spectrum antibacterial properties and had good in vitro inhibitory effects on five plant pathogenic bacteria, including Xcc. The EC₅₀ values were approximately 0.5 μg·mL^-1, indicating that a low concentration of PHMG could inhibit the growth of pathogenic bacteria. The EC₅₀ values of PHMG against 51 strains of Xcc ranged from 0.19 to 0.69 μg·mL^-1, and the in vitro antibacterial activity was relatively stable and reliable. The results of leaf inoculation showed that PHMG could protect citrus leaves from Xcc and had a therapeutic effect. The results of field trials showed that spraying PHMG (0.5 mg·mL^-1) had a control effect of about 60% on citrus canker, which was slightly lower than that of the control fungicides, kasugamycin-thiodiazole-copper and kasugamycin-oxine-copper. Furthermore, PHMG not only caused depressions on the surface of Xcc and abnormal cell size, but also promoted the apoptosis of Xcc, inhibited the formation of cell biofilm, and reduced the motility of Xcc.【Conclusion】 PHMG has excellent in vitro antibacterial activity against Xcc, and can effectively reduce the occurrence of citrus canker in the field in practical applications. In addition, PHMG affected the cell morphology, cell apoptosis, biofilm formation and motility of Xcc. The results of this study will provide important theoretical guidance for the subsequent application of PHMG for citrus canker and its expansion to other bacterial diseases.

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

Spatial Distribution Pattern and Transfer Function Construction of Soil Bulk Density in Nenjiang City, Heilongjiang Province

WANG BingJie, QIN ShiHan, LI DeCheng, HU WenYou, JIANG Jun, CHI FengQin, ZHANG Chao, ZHANG JiuMing, XU YingDe, WANG JingKuan

Scientia Agricultura Sinica. 2025, 58(9):  1791-1803.  doi:10.3864/j.issn.0578-1752.2025.09.009

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【Objective】 Given the unclear degree of "hardening" of cultivated soil and its spatial distribution in the typical black soil region of Northeast China, this study took Nenjiang City, Heilongjiang Province for example, the spatial distribution pattern of soil bulk density were predicted and analyzed, and the soil bulk density transfer function based on factors such as organic matter content and compaction was established. 【Method】 Pearson correlation analysis and principal component analysis were used to evaluate the importance of various factors on soil bulk density, the random forest model was employed for predictive mapping, and multiple soil bulk density transfer functions were constructed and compared for accuracy. 【Result】 Soil bulk density was significantly negatively correlated with water content and organic matter content, and was affected by multiple factors such as clay, sand, pH, average annual temperature, and average annual precipitation, but the impact of topography was relatively small. Forecast mapping revealed that the soil bulk density showed a gradually increasing trend from the northeast (1.08-1.17 g·cm^-3) to the southwest (1.30-1.40 g·cm^-3) in Nenjiang City, and the soil bulk density in the subsoil was higher than that in the topsoil. In addition, soil bulk density and soil compaction increased with soil depth, but the soil bulk density changed slowly (1.20-1.44 g·cm^-3), while the soil compaction increased rapidly mainly in the topsoil (0-20 cm) (the change amplitude was about 300 kPa). Besides, the binomial model and support vector machine had higher R² values in the fitting of organic matter-bulk density and compaction-bulk density, respectively, and had better fitting effects. In the subsoil, the prediction accuracy of the soil bulk density transfer function constructed by compaction (R²=0.55, RMSE=0.1) was higher than that of the model constructed by soil organic matter (R²=0.43, RMSE=0.12). 【Conclusion】 The soil bulk density in Nenjiang City showed a distribution trend of being low in the northeast and high in the southwest, and was affected by multiple factors such as soil properties, climate and topography. In addition, the compaction transfer function could be used as a rapid diagnostic method for changes in soil bulk density and the degree of "hardening" of the black soil region in Northeast China.

Effects of Fairy Rings on Carbon and Water Fluxes in Hulunbuir Meadow Steppe

TUDI YIMITI, YU HongLiang, WANG Xu, PING XiaoYan, WU YiQian, WANG ChongWei

Scientia Agricultura Sinica. 2025, 58(9):  1804-1815.  doi:10.3864/j.issn.0578-1752.2025.09.010

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【Objective】 This study aimed to investigate the spatial heterogeneity of vegetation and soil in the grassland fairy ring and its influence on the ecosystem carbon and water exchange characteristics. 【Method】 Using a measurement system consisting of Licor-6400 and static bright/dark boxes, the different components of plant community carbon and water fluxes were determined, including net ecosystem carbon exchange (NEE), ecosystem respiration (ER), and evapotranspiration (ET), and estimated grassland ecosystem gross primary productivity (GPP), carbon utilization efficiency (CUE), and water utilization efficiency (WUE). 【Result】 Plants on the fairy ring (green grass ring) were mainly dominated by Gramineae, Cyperaceae and Asteraceae, and the number of species and diversity index on the ring were significantly smaller than those inside and outside the ring (P<0.05). The above-ground biomass on the ring (324.72 g·m^-2) was significantly higher than those inside (184.66 g·m^-2) and outside (194.86 g·m^-2); while the below-ground biomass on the ring (340.55 g·m^-2) was smaller than those inside (508.29 g·m^-2) and outside (394.77 g·m^-2), and the root shoot ratio of the ring was significantly lower than that outside of the ring (P<0.05), which might be related to the cumulative effect of soil available nutrient on the fairy ring. The average contents of soil total nitrogen (STN), soil organic carbon (SOC), soil available potassium (SAK), soil available phosphorus (SAP), soil ammonium nitrogen (SAN) and soil nitrate nitrogen (SNN) were higher than those in and out of the ring to different degrees. GPP and NEE were significantly greater on the grassland fairy ring than in and out of the ring (P<0.05), and ER, ET, CUE and WUE were higher on the ring than in and out of the ring too, but the differences were not significant (P>0.05). Carbohydrate flux components GPP, NEE, ER and ET were positively correlated with above-ground biomass to different degrees; CUE and WUE were positively correlated with soil nutrients to different degrees. 【Conclusion】 The developmental process of fairy ring fungi changed the structural characteristics of grassland communities and the spatial pattern of soil nutrients, and the soil “fertilization effect” driven by fairy ring fungi was the fundamental reason for the spatial heterogeneity of carbon and water flux fractions and carbon and water use efficiencies in different layers of the fairy ring.

HORTICULTURE

Genetic and Interaction Analysis of High Soluble Solid Content Loci in Processing Tomato

ZHANG Min, LI Xin, ZHANG Yong, ZHONG DePing, LU XiaoXiao, HE ShuMin, CHEN DongHong, LI Ye, LI RongXia, HUANG ZeJun, WANG XiaoXuan, GUO YanMei, DU YongChen, LIU HongHai, LI JunMing, LIU Lei

Scientia Agricultura Sinica. 2025, 58(9):  1816-1829.  doi:10.3864/j.issn.0578-1752.2025.09.011

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【Objective】 This study aimed to explore the genetic effects and the interaction effects by utilizing the introgression lines with high soluble solid content sites, which could provide material and theoretical basis for genetic improvement of high-quality, gene pyramiding, and hybrid vigor prediction of tomatoes. 【Method】 Nine introgression lines (ILs) comprising high-SSC loci of S. pennellii LA0716 (IL1-4, IL2-6, IL4-4, IL5-4-5-44, IL7-3, IL7-5-5, IL8-3, IL9-2-5) and S. habrochaites LA1777 (LA3914) were selected to analyze the effects of genetic, intra-specific, and inter-specific interactions of soluble solids content, fruit weight, and plant yield. 【Result】 As the genetic effects, the high soluble solids loci contained in IL7-3 exhibit dominant effect, while the linkage drag of yield reducing show dominant effect. The high soluble solids loci in IL 9-2-5 exhibit dominant effect also, with the fruit weight and yield do not reduce. The yield increase loci in IL1-4 were over-dominant. The linkage drag loci responsible for reducing fruit weight in IL2-6 were dominant. In the interaction, some ILs or loci that can affect SSC and yield were selected. Such as, IL7-3 and IL9-2-5 have good epistatic and additive effects, both of which can significantly increase SSC in double hybrids, but the yield of double hybrids which contained IL7-3 was also reduced. IL2-6 can reduce the fruit weight of its interaction combination significantly. The yield of double hybrids which has IL5-4-5-44 or IL7-5-5 get increased. The alleles of IL1-4 and LA3914 both have better dominant or super-dominant effects on plant yield and horticultural yield. Our results showed that, the correlation between horticultural yield and plant yield was found to be high (with a correlation coefficient of 0.916). Thus, increasing SSC as part of genetic improvement must be performed under the premise of ensuring high yield.【Conclusion】 The total soluble solid content and horticultural yield could be improved effectively through pyramiding high soluble solids loci. In order to improve their interaction effects more effectively, the interaction of high soluble solids loci which has synergism in genetics and physiology could be better. Therefore, selecting suitable high solid content sites for multigene polymerization breeding is an effective way to improve the soluble solid content and yield of tomatoes.

FOOD SCIENCE AND ENGINEERING

Some Reflections on Modern Science of Agricultural Product Quality

JI ShengYang, LU BaiYi, LI PeiWu

Scientia Agricultura Sinica. 2025, 58(9):  1830-1844.  doi:10.3864/j.issn.0578-1752.2025.09.012

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Meeting the evolving demands of the public for the nutrition and quality of agricultural products is the eternal driving force and direction for high-quality agricultural development. Science of agricultural product quality has emerged in response to this need, which plays a crucial role in guiding the development of the agricultural industry and supporting rural revitalization. Based on a review of domestic and international research on agricultural product quality, this paper outlined the development history of science of agricultural product quality and introduced the concept of modern science of agricultural product quality. This concept focused on agricultural products such as grains, vegetables, aquatic products, dairy, fruits, meat, poultry, tuber and root, and medicinal food plants. By employing modern detection methods and analytical techniques, the core of this discipline was the nutritional quality and intelligent characterization of agricultural products. It aimed to establish a quality evaluation system for agricultural products based on different uses, elucidate the material basis and influencing factors of product quality, uncover the mechanisms of quality composition (structure-function) and quality formation (deterioration), and establish comprehensive control measures, thus producing high-quality agricultural products to meet consumer demand, guide processing, and improve agricultural industrial efficiency. From the perspective of industrial high-quality development and public health, the paper also analyzed the necessity of modern science of agricultural product quality research. Additionally, it identified key challenges in current agricultural product quality research, including: (1) Unclear spatiotemporal variation patterns and undefined characteristic quality, lack of evaluation technologies, and low precision and portability of detection technologies; (2) The complexity of agricultural product components, unclear relationships between spatial structure and quality characteristics, excessive processing, resource waste, and difficulty in premium prices for high quality; (3) Unclear quality influence patterns, unidentified molecular targets for formation and deterioration, and difficulty in controlling and maintaining quality. Based on these challenges, the paper proposed three major research areas in modern science of agricultural product quality, including agricultural products characteristic quality exploration and evaluation detection technologies, mechanisms of quality composition (structure-function) and high-value utilization technologies, and mechanisms of quality formation (deterioration) and control technologies. Finally, the paper outlined key future research tasks, including: (1) Constructing a database of agricultural product quality based on IoT, big data, and artifical intelligence technologies to achieve precise individual nutritional needs; (2) Building sensor networks and data collection systems driven by AI-powered supply chain technologies to achieve intelligent characterization of agricultural product quality throughout the entire industry chain; (3) Developing a green circular model system based on quality gradients and comprehensive utilization technologies to realize high-value resource transformation in the entire agricultural production process; (4) Creating an agricultural product AI intelligent system based on multi-source knowledge integration technologies for full-process quality control of agricultural products. This review aimed to provide the guidance and support for agricultural research, production, and management practices, addressing current bottlenecks in improving agricultural product quality, and contributing to the high-quality development of the agricultural industry.

ANIMAL SCIENCE·VETERINARY SCIENCE

Weighted Gene Co-Expression Network Analysis Reveals Potential Candidate Genes Affecting Fat Deposition in Pigs

WANG JiYing, LI JingXuan, WANG YanPing, GUO JianFeng, LIN HaiChao, ZHAO XueYan

Scientia Agricultura Sinica. 2025, 58(9):  1845-1855.  doi:10.3864/j.issn.0578-1752.2025.09.013

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【Objective】 Fat deposition is the major energy storage tissue in pigs, and its amount not only has a direct impact on the economic benefits of pig production, but also is closely related to the quality of pork. In this study, based on RNA sequencing data and phenotypic data of fat deposition related traits, a gene co-expression network was constructed to mine key candidate genes affecting pig fat deposition and to explore the potential regulatory mechanism of pig fat deposition. 【Method】 RNA sequencing was performed on the longissimus dorsi samples of 28 Duroc pigs. Phenotypic data of these pigs regarding fat deposition-related traits were measured and calculated, including backfat thickness, fat percentage, intramuscular fat (IMF) content, and body mass index (BMI). Weighted gene co-expression network analysis (WGCNA) was conducted using an R language WGCNA package based on the RNA sequencing data and these phenotypic data to identify critical genes from co-expression modules related to fat deposition. 【Result】 WGCNA identified a total of 28 co-expression modules, among which Cyan and Purple modules were strongly correlated with at least two fat deposition-related traits based on the criteria of |module-trait relationships| >0.3 and module gene significance >0.25. Functional enrichment analysis revealed that genes in Cyan module were significantly enriched in fat deposition-related pathways, such as fatty acids biosynthesis (adjusted P value = 3.48E-02) and glycosphingolipid biosynthesis (adjusted P value = 4.40E-02). In contrast, those genes in Purple module were not significantly enriched in any fat deposition-related pathways and GO terms (adjusted P value >0.05). Furthermore, combining the criteria of intra-modular connectivity greater than 0.2, an absolute correlation coefficient of gene expression with module eigengene exceeding 0.8, and the absolute correlation coefficient of gene expression with at least two fat deposition-related traits greater than 0.3, 24 hub genes of 92 genes in this fat deposition-related module were identified. Among these hub genes, the correlation coefficients between the expression of four genes, including BET1L, NAGLU, B3GALT4, and TMEM115, and four fat deposition-related traits, backfat thickness, fat percentage, IMF content, and BMI, were all greater than 0.3. Moreover, gene function annotation showed that the biological function of these genes were closely related to fat deposition. These results indicated that the four genes might play essential roles in fat deposition. 【Conclusion】 In this study, WGCNA was applied to Duroc pigs, resulting in the discovering a co-expression module closely associated with fat deposition-related traits. Within this module, four potential candidate genes affecting fat deposition were identified, namely BET1L, NAGLU, B3GALT4, and TMEM115. These findings not only deepened our understanding of the genetic factors involved in fat deposition, but also provided a solid theoretical reference for further exploration of the underlying mechanisms of fat deposition in pigs.

Research Progress on the Application of Mid-Infrared Spectroscopy Analysis Technology in Predicting Methane Emissions from Cows

YANG GuoChang, ZHENG Yue, BAO XiangNan, DAI YingChun, WANG JinGang, BAI XueFeng, SUN Wei, LI XiHe, ZHANG ShuJun

Scientia Agricultura Sinica. 2025, 58(9):  1856-1866.  doi:10.3864/j.issn.0578-1752.2025.09.014

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The emission of greenhouse gases not only leads to global warming and changes in the climate system but also may cause damage to the ozone layer, thereby exacerbating the greenhouse effect. Although the total emissions of methane gas are not as high as carbon dioxide gas, and its residence time in the atmosphere is relatively short, it possesses a higher global warming potential, making it a highly threatening greenhouse gas. Livestock farming is a major source of anthropogenic methane gas emissions, with the methane emissions from cows accounting for nearly one-fifth of the total proportion. Given this context, the measurement of individual cow methane emissions becomes crucial. Understanding the methane emissions produced by each cow can help identify cows with high emissions and implement more targeted measures to reduce emissions. Therefore, there is a need for convenient high-throughput technologies for measuring cow methane emissions. Traditional methane measurement techniques, such as respiration chambers and sulfur hexafluoride gas tracing technology, are time-consuming, labor-intensive, and costly, which hinders the monitoring of methane emissions on a large scale for individual cows. Using a combination of cow trait indicators to predict the methane emission characteristics of cows is a feasible alternative method. Numerous methane prediction equations based on factors, such as cow energy intake, dry matter intake, and daily feed composition, have been developed. However, these prediction factors are also challenging to collect on commercial farms, limiting the feasibility of these equations for large-scale applications. Considering that mid-infrared spectroscopic information of cow milk can be obtained in bulk and at low cost from routine cow production performance assessments, foreign researchers have been exploring the feasibility of predicting cow methane emissions based on mid-infrared spectroscopic information from cow milk over the past decade. It has been confirmed that using mid-infrared spectroscopy to predict cow methane emissions is feasible, biologically plausible, and moderately accurate. However, the researchers in this area have not yet begun in China. This paper elaborated on the current research status of predicting cow methane emissions using mid-infrared spectroscopic information from cow milk and emphasized the key points and challenges that need to be addressed in future research. It summarized the different strategies adopted by various studies in terms of cow methane emission measurement indicators, methane phenotype observation value determination methods, mid-infrared spectroscopy data collection, modeling methods, and validation strategies, aiming to provide insights for Chinese researchers conducting related studies.