Association Analysis Of Heading Date In 262 Wheat Natural Populations

Wheat heading date is an important agronomic traits,and appropriate heading date can ensure high and stable yields.Identifying molecular marker of heading date can provide a theoretical basis for breeding wheat varieties with wide adaptability.A total of 334 SSR markers were used to analyze genotype of natural populations including 262 germplasm resources.A total of 84 markers which evenly distributed on wheat 21 chromosomes was selected for population genetic structure analysis.The determination of field phenotype was conducted in 2014 and 2015.Molecular markers associated with wheat heading date were identified by using general linear model(GLM)and mixed linear models(MLM)in Tassle software.The results shown that 26 markers were detected and their contribution rate was 5.9%-21.97%.Among them,six loci located on 1AS(Xbarc28),2AL(Xwmc658),2BS(Xbarc7),3BL(vp1-b2,Xgwm114,Xgwm131),5BL(Xgwm499),6DS(Xbarc173)were detected simultaneously in two years and their contribution rate was more than 11%,which were regarded as relatively higher and stable loci.In addition,marker locus located on chromosomes 1AS has not been reported,we give a preliminary presumption that it is likely to be a novel site associated with heading date.