Study On The Genetic Variation Of The Wheat Mutant Dms

Plant stem,stamen and pistil are three important organs of wheat,their developments significantly affect grain yield.A novel natural mutant of dwarf,multi-pistil and male sterility dms was previously reported by us.However,what genetic changes have occurred in dms was unclear.To settle this issue,SNP association analysis by Bulked Segregant RNA-Sequencing(BSR),SSR marker assay,chromosome counting,and high-resolution chromosome fluorescence in situ hybridization(FISH)techniques were employed in this study.By comparing the tall plants(T)with dwarf plants(D)in the offspring of dms mutant,SNP association analysis indicated that the most different SNPs were on chromosome 2A.Later,SSR assay showed that 5 SSR markers Xbarc212,Xbarc122,Xgwm95,gwm445 and gwm294 on 2A were polymorphic between T,M and D.Chromosome counting confirmed there were 3 types of chromosome numbers in the offspring of dms,42,41 and 40 respectively.High-resolution chromosome painting analysis demonstrated that T plants had all 42 wheat chromosomes;the medium plants(M)had 41 chromosomes,absented one chromosome 2A;D plants had 40 wheat chromosomes,absented both 2A.Thus T is a normal wheat line,M is a 2A monosomic line and D is a 2A nullisomic line.These data demonstrated that dms was resulted from 2A absenting.Obviously,there are very important genes on 2A to determine wheat stem,stamen and pistil development.Because D plants can be used as a female parent to cross with other wheat genotypes,dms is a unique germplasm for gene functional study about chromosome 2A and wheat design breeding point at 2A.