Precisely mapping a major QTL for grain weight on chromosome 5B of the founder parent Chuanmai42 in the wheat-growing region of southwestern China
作者：Ye MJ#, Wan HS#, Yang WY, Liu ZH, Wang Q, Yang N, Long H, Deng GB, Yang YM, Feng H, Zhou YH, Yang CR,LiJ*,ZhangHQ*.
Abstract:Increasing the thousand-grain weight (TGW) is considered to be one of the most important ways to improve yield, which is a core objective among wheat breeders. Chuanmai42, which is a wheat cultivar with high TGW and a high and stable yield, is a parent of more than 30 new varieties grown in southwestern China. In this study, a Chuanmai42-derived recombinant inbred line (RIL) population was used to dissect the genetic basis of TGW. A major QTL (QTgw.saas-5B) mapped to theXgwm213–Xgwm540interval on chromosome 5B of Chuanmai42 explained up to 20% of the phenotypic variation. Using 71 recombinants with a recombination in theQTgw.saas-5Binterval identified from a secondary RIL population comprising 1818 lines constructed by crossing theQTgw.saas-5Bnear-isogenic line with the recurrent parent Chuannong16,QTgw.saas-5Bwas delimited to a 0.6 cM interval, corresponding to a 21.83 Mb physical interval in the Chinese Spring genome. These findings provide the foundation forQTgw.saas-5Bcloning and its use in molecular marker-assisted breeding.Precisely mapping a major QTL for grain weight on chromosome 5B of the founder parent Chuanmai42 in the wheat-growing region of southwestern China.
Key message:QTgw.saas-5Bwas validated as a major thousand-grain weight-related QTL in a founder parent used for wheat breeding and then precisely mapped to a 0.6 cM interval.