QTL Analysis of Grain Quality Related Traits Using Recombinant Inbred Lines (RILs) Derived from the Cross of Triticum polonicum L. Line XN555×T. aestivum L. Line Zhong 13
Abstract：The characteristics related grain quality in Triticum aestivum L. are quantitative traits controlled by polygenic. To investigate the genetic basis of Triticum aestivum L. quality traits, the QTLs for grain hardness(GH), grain protein content(GPC), flour protein content(FPC) and wet gluten content(WGC) were analyzed in a population which consisted of 99 F10 recombinant inbred lines (RILs) derived from the cross Triticum polonicum L. line XN555 and T. aestivum L. line Zhong 13. The results showed that the differences between line XN555 and Zhong 13 about GH, GPC and FPC were highly significant difference(P＜0.01) in 2012 and 2013. WGC had highly significant difference(P＜0.01) between line XN555 and Zhong 13 in 2012 and significant difference(P＜0.05) in 2013. The analysis of variance (ANOVA) indicated that there were highly significant differences among RILs about GPC, FPC and WGC and significant differences about GH both in 2012 and 2013. Based on the linkage map constructed with single sequence repeat (SSR) makers, the software Icimapping v3.2 and the inclusive composite interval mapping were used to identify QTL for quality related traits. Two hundred and forty one markers were located to the 14 linkage groups including genome A and B. This map spanned 1 338.92 cM with the average distance of 5.56 cM between any 2 markers. The QTLs for quality related traits, i.e. GH, GPC, FPC and WGC , were detected based on the phenotypic in 2012 and 2013. A total of 24 additive QTLs with the genetic distance from 0.00 to 5.70 cM away from the nearest markers were detected on 9 chromosomes, including 1A, 3A, 4A, 5A, 6A, 1B, 2B, 3B and 5B. Five QTLs for GH located on chromosomes 1A, 1B and 5A, respectively. Single QTL for GH could account for phenotypic variations from 7.93% to 30.49%. Among these, the QTLs on 1A and 1B were identified both in 2012 and 2013. Seven QTLs for GPC were located on chromosomes 6A, 1B, 2B, 3B and 5B, respectively. Single QTL for GPC could account for phenotypic variations from 8.30% to 29.69%. Two of the seven QTLs for GPC were detected in the interval of Xbarc104~Xcfa2114 on chromosome 6A based on the phenotypic of the two years. Seven QTLs for FPC were found on chromosomes 3A, 4A, 6A, 1B, 2B and 5B, respectively. Single QTL for FPC could account for phenotypic variations from 6.90% to 29.50%. Two QTLs for FPC on chromosome 5B were found by using the phenotypic of the two years. Five QTLs for WGC were found on chromosomes 6A, 1B, 2B and 5B, respectively. Single QTL for WGC could account for phenotypic variations from 10.10% to 18.43%. In the interval of Xbarc104~Xcfa2114 on chromosome 6A, with genetic distances of 1.2 cM from the nearest marker Xbarc104, two QTLs for WGC were detected both in 2012 and 2013. Meanwhile, one QTL for FPC in 2012 and one QTL for GPC in 2013 were detected in the same interval as well. The identified molecular markers related to the quality traits in this study will benefit the marker-assisted selection in breeding programs.
