Identification of a High-Yield Introgression Locus from Synthetic Hexaploid Wheat in Chuanmai 42

Abstract

Synthetic hexaploid wheat,a carrier of many elite genes,is an important genetic resource in the improvement of common wheat(Triticum aestivum L.).Chuanmai 42 is a wheat cultivar with high-yield potential and resistance to strip rust(Puccinia striiformis f.sp.tritici),which was developed by crossing and backcrossing Syn769(an elite synthetic hexaploid wheat) with Sichuan commercial wheat cultivars.For understanding the genetic effects of the introgression loci of synthetic hexaploid wheat in Chuanmai 42,a total of 78 introgression loci of synthetic hexaploid wheat were identified in Chuanmai 42 by scanning using 1029 SSR markers.Using 127 recombinant inbred lines(RILs,F8) with Chuanmai 42(introgression loci) and Chuannong 16(Chuannong 16 loci) backgrounds,the genetic effects of the introgression loci were evaluated across six environments in Sichuan Province,China from 2006 to 2009.One high-yield potential locus Barc1183 derived from the synthetic hexaploid wheat was detected in Chuanmai 42.It was further located on the long arm of 4D chromosome using the 4DS and 4DL telosomic lines of Chinese Spring and the 4D(4A) and 4D(4B) substitution lines of Longdon.This locus had positive effects on increasing tiller number per plant,number of effective spikes,grain number per square meter,harvest index,and grain production rate,and the average yield was increased by 8.92% compared with Chuannong 16 in the six growing environments.Therefore,the introgression locus Barc1183 of synthetic hexaploid wheat can be useful for breeding high-yield potential wheat.