冀北坝上大豆结瘤相关性状全基因组关联分析OA北大核心CSTPCD

[Objective]Exploring efficient nodulation soybean germplasm adapted to the ecological conditions of the Bashang area,identifying genetic loci and candidate genes regulating soybean-rhizobium symbiotic nodulation,and improving soybean symbiotic nitrogen fixation efficiency.[Method]This study utilized a natural population of 260 soybean germplasms as the research object,rhizobium strain USDA110 was inoculated under outdoor potted conditions in the Bashang of Hebei Province.The single plant nodule number and single plant nodule dry weight data were used as phenotypic values.Combined with genotype data of the 260 germplasms,a genome-wide association analysis was conducted to explore genes related to soybean-rhizobium symbiotic nodulation.[Result]A total of 18 SNPs significantly associated with soybean nodule number were detected,located on chromosomes 2,7,8,13,18,and 19.Among them,the significant associated locus BARC_2.01_Chr02_43161654_A_G on chromosome 2 was identified as the main locus controlling soybean nodule number(LOD=3.89).Linkage disequilibrium analysis within the 200 kb interval upstream and downstream of this locus containing BARC_2.01_Chr02_43161654_A_G identified 10 candidate genes regulating soybean nodule number.There was a significant difference in the number of nodules among the materials corresponding to different haplotypes of Glyma.02G243200(P＜0.05),the expression pattern of this gene was queried in the SoyBase database,and it was expressed in root hairs,indicating that Glyma.02G243200 may be a key gene influencing soybean nodule number.Additionally,six SNPs significantly associated with soybean nodule dry weight were identified,located on chromosomes 6,18,and 20.Among them,the significant associated loci BARC_2.01_Chr06_6069381_G_A and BARC_2.01_Chr06_6192925_T_C on chromosome 6 were identified as the main loci controlling soybean nodule dry weight(LOD=3.49 and LOD=3.35,respectively).Linkage disequilibrium analysis within the 100 kb interval upstream of BARC_2.01_Chr06_6069381_G_A and downstream of BARC_2.01_Chr06_6192925_T_C identified 14 candidate genes regulating soybean nodule dry weight.Haplotype analysis revealed significant differences in nodule dry weight for the genes Glyma.06G079600 and Glyma.06G079900 between different haplotype materials(P＜0.01,P＜0.001),the expression pattern of this gene was queried in the SoyBase database,and they were expressed in roots,indicating that these two genes may be key genes influencing soybean nodule dry weight.[Conclusion]This study identified a candidate gene significantly associated with nodule number on chromosome 2 and two candidate genes significantly associated with nodule dry weight on chromosome 6,providing new genetic resources and references for genetic improvement of soybean nodulation traits.