Abstract:

【Objective】So in view of this, our project aims to explore excellent salt tolerant soybean germplasm resources and identify stable expression sites related to salt tolerance.【Methods】In this study, 250 mmol/L NaCl solution was used to simulate the saline-stressed growth environment, and treat 301 soybean seedlings. 7 days later,five traits including total number of roots, number of root tips, total length of roots, root fresh weight,root dry weight were measured and then salt tolerance of soybean seedling was evaluated by principal component analysis(PCA), membership function analysis, and cluster analysis based on stress indices of various indicators, and finally, genome-wide association analysis(GWAS)was conducted based the root trait value under different treatment conditions.【Results】According to the strength of salt tolerance, the 301 materials could be divided into 4 categories. 4 strong salt tolerant varieties were classified as the first category, 73 salt tolerant varieties classified as the second category, 137 moderate salt tolerant varieties classified as the third category, and 87 salt sensitive varieties classified as the fourth category. GWAS showed that under normal treatment, two significant SNP loci were detected in root fresh weight, total root length, and total root number. A total of 7 SNP loci that might be associated with salt tolerance traits in soybean roots were detected under salt stress conditions, including the total number of roots and the number of root tips.【Conclusion】The phenotype of soybean root system is closely related to soybean salt tolerance, and screening sites related to salt tolerance through GWAS provides effective basis for the cultivation of new salt tolerant soybean varieties. A total of 9 significant SNP loci possibly related to salt tolerance traits in soybean roots were detected.

Key words: soybean; root; salt tolerance; membership function; GWAS

摘要：

【目的】挖掘优异的耐盐大豆种质资源并筛选出与耐盐有关且稳定表达的位点,为耐盐大豆新品种的培育提供有效依据。 【方法】使用250 mmol/L NaCl溶液模拟盐胁迫生长环境,对301份大豆幼苗进行处理,7 d后,检测根总数量、根尖数量、根总长、根部鲜重和根部干重5个指标,计算各指标胁迫指数并应用主成分、隶属函数和聚类分析法对大豆幼苗耐盐性进行综合评价,结合不同处理条件下根系各指标测量值进行全基因组关联分析(GWAS)。【结果】按照耐盐性强弱将301份大豆品种分为4类:4份强耐盐品种为第1类,73份耐盐品种为第2类,137份中等耐盐品种为第3类,87份盐敏感品种为第4类。正常培养条件下,在大豆根部鲜重、根总长和根总数量共检测到2个可能与大豆根系耐盐性状相关联的SNP位点。盐胁迫条件下,根总数量和根尖数量共检测到7个可能与大豆根系耐盐性状相关联的SNP位点。【结论】大豆根系表型与大豆耐盐性密切相关,可通过全基因组关联分析筛选与耐盐有关的位点,共检测到9个可能与大豆根系耐盐性状相关联的显著SNP位点。

关键词: 大豆, 根系, 耐盐性, 隶属函数, 全基因组关联