Abstract:

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 83 622 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.

Key words: soybean, Sichuan-Chongqing region, tolerance to acid aluminum, association analysis