川渝大豆耐酸铝抗性的鉴定和全基因组关联分析

Identification and genome-wide association analysis for tolerance to acid aluminum using Sichuan and Chongqing soybean germplasm

为发掘川渝地区耐酸铝大豆抗性资源和相关候选基因,选用201份川渝地区的大豆育成和地方品种,以主根相对伸长率作为耐酸铝的指标,采用水培法进行大豆幼苗期抗性鉴定,结合83622个SNP标记对该性状进行全基因组关联分析。结果表明,201份川渝大豆资源的主根相对伸长率均值为77.0%,变异幅度在13.0%~98.6%之间,变异系数为17.6%,广义遗传率为93.2%。其中,6份大豆资源的主根相对伸长率在95.0%以上,表现出极高的耐酸铝抗性。2份资源的主根相对伸长率小于20.0%,对酸铝环境极敏感。以0.0001作为显著关联位点的阈值,采用GLM和MLM两种模型同时检测到了4个SNP位点,分别位于2号、11号、20号染色体上的4个单倍型块内。同时,在4个单倍型块内检索出7个候选基因,参考区间内基因的功能注释和转录组表达水平,预测Glyma.02g211800和Glyma.20g185500是大豆耐酸铝应答和生理调控的候选基因。

In order to find out acid aluminum tolerance soybean germplasm in Sichuan-Chongqing region,and to discover candidate genes for tolerance,201 soybean bred lines and local varieties from Sichuan-Chongqing region were selected and identified.Hydroponic experiment was carried out to identify seedling tolerance using relative elongation of the main roots as index.Genome-wide association analysis was performed using 83622 SNP markers.Results showed that the average relative elongation of the main roots of 201 Sichuan-Chongqing resources was 77.00%,the variation range was 13.0% to 98.6%,the coefficient of variation was 17.6%,and the generalized heritability was 93.2%.Among them,the relative elongation of the main roots of 6 soybean lines were above 95.0%,showing extremely high tolerant to acid aluminum.The relative elongation of the main roots of 2 resources were less than 20.0%,indicating their extreme sensitive to acid aluminum environment.Using 0.0001 as threshold of significant association sites,4 SNP sites were detected simultaneously.Using GLM and MLM models,the 4 SNPs were located in the 4 haplotype blocks on chromosomes 2,11,and 20,respectively.Seven candidate genes were searched from 4 haplotype blocks.With reference to the functional annotation and transcription expression level of the candidate genes,it could be predicted that Glyma.02g211800 and Glyma.20g185500 were candidate genes for soybean acid aluminum tolerance response and physiological regulation.