Abstract
Quantitative trait locus (QTL) mapping associated with wheat drought and heat tolerances was characterized in this study. There were 25, 25, 23 and 17 QTLs controlling chlorophyll content, leaf water content, spike grain weight and thousand-kernel weight, respectively. The QTLs related to drought tolerance were located on 7 wheat chromosomes with a phenotypic contribution rate of 9.38–34.20%, related to heat tolerance on 9 wheat chromosomes with a phenotypic contribution rate of 9.03–35.55%, and related to combined drought and heat tolerances on 11 wheat chromosomes with a phenotypic contribution rate of 9.09–33.11%, respectively. Among them, 35 QTLs were newly located, in which 16 were associated with heat tolerance, and 19 associated with combined drought and heat tolerances. We found 2 overlapping sites related to drought tolerance on chromosomes 2A and 3B, 3 overlapping sites related to heat tolerance on chromosomes 2A, 7B and 6D, and 4 overlapping sites related to combined tolerances for drought and heat on chromosomes 2A, 2B and 4D. The overlapping QTLs with stable expression under different environmental stresses were located on chromosomes 2A (gwm294-wmc644), 3B (wmc808-wmc78) and 7B (wmc83-wmc276). The overlapping loci involving in pleiotropism or a close linkage have high phenotypic contribution rates and environmental stability.
Mapping and genetic overlapping of QTLs related to drought and heat tolerances in spring wheat