Genome-wide Association Study Of Yield Traits In Some Varieties Of Huang-huai Wheat

Genome-wide association study is a technique based on LD to identify the relationship between plant traits and target genes.In this study,52 Huanghuai wheat cultivars(lines)were used to measure six important phenotypic values about yield-related traits,such as the plant height(PH),spike length(SL),number of spikes per plant(SNP),fertile spikelets(FSS),grain number per spike(GPS)and thousand kernel weight(TKW)in two years.This experiment analyzed the germplasm genetic diversity and population genetic structure of the tested materials,and used 248 pairs of SSRs(Sequential Sequence Repeats)and SNPs(Single Nucleotide Polymorphisms)covering the whole genome for genome-wide association study.The results are as follows:1.The phenotypic analysis showed that the discrepancies in the six traits of wheat materials reached a significant level(P<0.01).The yield decreased from Henan,Jiangsu and Shaanxi between the regions.The trend of the six important yield traits was basically same.In the discrepancies' level,the average spike length and number of spikes per plant and the coefficient of variability were the highest.The discrepancies' level of the fertile spikelets,grain number per spike were the second and the plant height weight,thousand kernel weight was the smallest.2.By genotypic analysis,a total of 899 alleles were detected,the average allelic richness is 3.625,the genetic diversity index ranges from 0.301 to 0.715,and the average value is 0.586;the average value of polymorphism information content(PIC)is 0.510,which reaches a highly polymorphic(PIC ? 0.5)level.3.Population genetic structure analysis and cluster analysis showed that the test materials' population was clustered into four sub-groups,and the sub-groups were largely the same in these two methods of analysis.The results of the sub-groups showed that the materials in each group had nothing to do with the geographical origin of the varieties.4.Through genome-wide association study,8162 paired sites were detected in the mixed linear model(MLM)combining with yield-related traits and molecular markers.These paired sites includes 113 pairs of marker-trait collinear sites.There were 108 collinear linkage sites in the SSR markers(P<0.01),and 7 pairs of linkage sites were detected in the SNP markers(P<0.045).There were 66 significant association markers,among which 11 pairs were closely linked(P<0.01).These markers can provide references for subsequent association analysis and positioning,and provide basis for further exploration and utilization of excellent genetic breeding.