Chromosomal localization of the genes controlling quantitative traits of drought resistance in wheat using substitution lines

The first step in identification of genes which control traits in stress and no stress conditions is localization of chromosomal related to traits. In order to locate the genes controlling drought resistance and screening quantitative indices of drought resistance in wheat, substitution line series of Hope into the genetic background of Chinese Spring (CS) were tested in a randomized complete block design with three replications under two irrigated and water stress conditions. Based on the potential (Yp) and stress (Ys) grain yield, criteria of drought tolerance such as: mean productivity (MP), tolerance index (TOL), geometric mean productivity (GMP), stress susceptibility index (SSI) and stress tolerance index (STI) were estimated. The results exhibited high significant differences among the lines for traits studied indicating the presence of genetic variation and possibility of determination of the genes controlling these traits on the related chromosomes. The results of mean comparison showed that most of the genes controlling yield and yield components in the non-irrigated conditions are located on the chromosomes 6A, 7A, 3D, 2B, 7D and 7B. The results of correlation analysis between indices، potential and stress yield showed that the most suitable criteria for screening substitution lines were MP, GMP and STI. Evaluation of biplot and three dimensional plots indicated that most of the genes controlling MP, GMP and STI are located on chromosomes 1A, 6B, 4D, 7A, 7B, 7D, 6A, 2B and 3D. To determine the genetic distance and to group the substitution lines, cluster analysis showed that the substitution lines 6A, 7A, 3D, 4D, 7D, 7B, 2B and Hope were in one group supporting the results of 3-D and biplot that they can be used for improvement of drought tolerance in Wheat.