Using KASP Marker To Mapping The Awnless Locus Awn-4A.1 In Wheat Variety Chinese Spring

As one of the most important food crops in the world,wheat?Triticum aestivum L.?has undergone a series of long domestication process.As one of the important photosynthetic organs in the spike of wheat,awn is the product of wheat long-term evolution and adaptation to the environment,which is of great significance for wheat yield and stress adaptation.In order to explore the genetic mechanism of awn development and awn growth,a F₂segregation population and a F₅ recombined inbred line?RIL?were constructed using the awnless wheat cultivar Chinese spring as the male parent and long awn variety MK147 as the female parent.The genetic analysis and molecular marker mapping of awn inhibitory genes were performed.The results of related research are as follows:Stereomicroscope observation of young spikes showed that the awn primordium appeared in the pistil and stamen differentiation stage of wheat;the parent awn primordia appeared to be different in the drug differentiation stage,the awn primordium of MK147began to grow,while the awn of CS was almost unchanged.It indicated that the awnless phenotype of CS was caused by the non-elongation of awn primordium.Genetic analysis of the progeny population of CS and MK147 show that all F₁generations had awn,and the awn length was between the two parents.Chi-square analysis of the awn length in F₂ population showed that the awnless and awned individuals conform to the 1:3 separation ratio,chi-square analysis of the RIL population show that the awnless plant and the awned plant met a 1:1 separation ratio.Indicated that the awnless in CS was controlled by a semi-dominant single gene.By using Wheat660K SNP chip combined with Bulk segregate analysis?BSA?,a polymorphic SNP marker enriched region was detected in the awnless and awned extreme bulks constructed by F₂ population,and the QTL was initially located on 4A chromosome.A total of 58 KASP markers were designed and developed in this QTL region.Finally,the mapping region was narrowed to between the KASP markers SNP-1537 and SNP-4195 with a genetic distance of 0.81 c M,corresponding to 9.23 Mb?4A:100.56-109.79 Mb,IWGSC.Ref.v1.0?on the Chinese spring reference genome 4A chromosome,and the locus was named Awn-4A.1.