Genome-Wide Association Analysis Of Low Phosphorus Tolerance Related Traits In Soybean Seeding

As an important grain and oil crop in the world,soybean[Glycine max(L.)Merr.]provides abundant protein and oil for human beings and is widely grown around the world.However,the yield of soybean has been low,and low phosphorus stress is one of the main factors influencing the yield of soybean.It is considered to be one of the most economical and effective methods to solve low phosphorus problems by molecular improved breeding of plants and combining traditional breeding to improve the low phosphorus tolerance of plants.However,there are few studies on the tolerance of low phosphorus in soybean,mainly focused on linkage analysis.Compared with linkage analysis,association analysis has the advantages of short test period,large detection breadth and high positioning accuracy.However,there are relatively few studies on soybean tolerance to low phosphorus by association analysis.In this study,a nature population consisting of 272 soybean accessions is used to identify and analyze phenotypes through three batches of a field experiments in two years,Genome-wide association analysis is conducted with NJAU 355K SoySNP chip for low tolerance related traits.We predict and analysis of related candidate genes based on identified intervals and functional annotations of stable associated SNPs.The main results are as follows:1.Phenotypic variation of soybean seedling-related traits:After low phosphorus stress treatment,the shoot dry weight,root dry weight and total dry weight of plants decreased overall,and the productions of plant photosynthese were more transferred to the roots,resulting in an increase in root to shoot ratio.The phenotypic variation are mainly caused by genetic factors.The ratios of four traits had wide range of phenotypic variation,exhibiting a normal or near normal distribution,showing the characteristics of quantitative traits.2.Genome-wide association analysis of low phosphorus related traits:Genome-wide association analysis is performed using 207,608 high quality SNPs on the relative-shoot dry weight,relative-root dry weight,relative-total dry weight,and relative-root to shoot ratio.A total of 21 SNPs were identified to be significantly associated with the related traits,and 5 SNPs were stably associated with the related traits on which mainly distribute on chromosome 18.3.Candidate gene prediction:Physical site intervals of the stably correlated SNPs were compared with Williams82 soybean genome,Combined with Arabidopsis gene function annotation information,thirty-six genes related to low phosphorus tolerance were screened.Among these genes,six genes relate to transferases,five genes relate to hydrolases,two genes relate to oxidoreductases,one gene associate with isomerases,eight genes associate with transporters,five genes relate to signal transductions,two genes relate to binding proteins,three genes relate to transcription factors and fours genes relate to other mechanisms.