Mining Of Genetic Loci And Genes Associated With Phosphorus Efficiency At Different Development Stages In Soybean

Soybean is an important crop which providing high quality food protein and oil for humans.However,in recent years,the lack of available phosphorus in soil has become an important limited factor for the yield and quality increasing in soybean.Therefore,the mining of genetic loci and candidate genes and cultivation of new varieties with high phosphorus efficiency become the effective strategy to solve the problems above.In view of this,one natural population was used in this study to mine the genetic loci and candidate genes associated with phosphorous efficiency at two critical phosphorus-demanding stages through the genome-wide association study,aimed to provide the selective markers and candidate genes for molecular genetic improvements of soybean phosphorus efficiency in future.The main results were as follows:1.The genetic variations and correlations of eleven phosphorus efficiency related traits were analyzed at two critical phosphorus-demanding stages(T1 and T2)under different phosphorus conditions(low and adequate phosphorous treatments),and eight high phosphorus efficiency germplasms were selected.The eleven related traits(shoot dry weight,root dry weight,root phosphorus content and phosphorus efficiency,etc)showed the significant or extremely significant differences between the two phosphorus treatments,and showed much higher genetic variations with the coefficient of variations ranging from 11.67%to 41.31%.Meanwhile,the characteristics of root shoot ratio,root fresh weight,dry weight and phosphorus efficiency at T1 and T2 stages under low phosphorus condition showed relative significant higher values than that under adequate phosphorus condition.Many significant or extremely significant correlations were also be found among the eleven related traits,such as the shoot fresh and dry weights,root fresh and dry weights,total fresh and dry weights.In addition,some elite soybean germplasms with high phosphorus efficiency were screened such as CJ02,Jidou18,Jidou7,Guandou6,Kefeng6,06B3,Luguandoul and Lu697-13-1.2.Two hundred and thirteen pleiotropic SNPs associated with soybean phosphorus efficient related traits were identified at the two critical stages,and 105 pleiotropic SNPs were detected in T1 stage,108 pleiotropic SNPs were detected in T2 stage.Among these SNPs,one SNP cluster(s715611375,ss715611377,ss715611379 and ss715611380)located on chromosome 12 was identified to significantly associated with plant height under low phosphorus condition at T1 stage,and the elite haplotype was screened out.Meanwhile,one pleiotropic SNP cluster(ss715606501,ss715606506 and ss715606543)on chromosome 12 was found to significantly associate with root shoot ratio,root dry weight and total dry weight under low phosphorus condition at T2 stage,and also the elite haplotype was analyzed.Furthermore,six co-associated SNPs were identified at T1 and T2 stages,and the SNP ss715597964,ss715607012,ss715622173 and ss715602331 were all detected under low phosphorus condition at two critical stages.3.Thirty-eight candidate genes controlling the phosphorous efficiency related traits were identified nearing the associated pleiotropic SNPs,which including the purple acid phosphatase and phosphorylase genes,the glucose 6-phosphate gene and malate transportation related genes.Most of these candidate genes showed direct or indirect interactions,and some genes could specifically expressed in soybean leaves,flowers,pods,roots and nodules.Furthermore,some related genes were selected through the results of transcriptome data for the strongly induced expression levels under low phosphorus condition,such as Glyma.08g291600,Glyma.08g342600,Glyma.10g144200,Glyma.10g252300 and Glyma.12g111800,which indicated that these genes associated with high phosphorus efficiency in soybean.In summary,one natural population was used to identify the genetic loci and candidate genes with soybean phosphorus efficiency related traits.The results showed that the relative wide genetic variations and significant correlations of eleven phosphorus efficiency related traits were found,and 213 pleiotropic SNPs associated with related traits were identified,including six co-associated SNPs at different stages.Furthermore,thirty-eight candidate genes were identified nearing the associated SNPs,and some related genes were strongly induced by the low phosphorus stress.