Detection of Quantitative Trait Loci for Grain Yield and Yield Components Across Environments in Durum Wheat

Abstract

Grain yield is considered to be polygenic and influenced by the environment. Quantitative trait loci (QTLs) mapping experiments conducted in several environments might increase the understanding of genotype x environment interactions and improve the selection response in wheat breeding. The objectives of this study were both to compare the QTLs for grain yield and yield component traits detected in a population of durum wheat evaluated in different environments, and to investigate the relationship among the genetic factors controlling these traits. A set of recombinant inbred (RI) lines was evaluated for grain yield and test weight in four trials and for grain yield components in eight trials. By using a linkage map of 217 loci, a total of 52 QTLs was detected that were significant in at least one environment at P≤0.001 or in at least 2 environments at P≤0.01. QTLs for multiple traits were detected in 13 of 19 chromosomal regions, suggesting pleiotropic effects of single QTLs or the effects of tightly linked QTLs controlling yield components. Evidence of genotype x environment interaction was found by comparing QTL maps of the same population grown in several environments.