Mapping QTLs for Heat Tolerance in Wheat

Heat stress is a major environmental stress limiting wheat productivity in most cereal growing areas of the world. In order to map and characterize quantitative trait loci controlling heat tolerance, 144 recombinant inbred lines deriving from the cross of Kauz and MTRWA116 were assessed in a greenhouse and growth chamber at 35°C. One hundred and sixty six SSR and 3 AFLP markers were used to construct a linkage map containing 18 linkage groups and covering 16 chromosomes of wheat. Using the composite interval mapping method, three QTLs were detected for heat tolerance and measured by the Fischer susceptibility index, on chromosomes 1B, 5B and 7B. The alleles of both parents contributed to heat tolerance. A large amount of explained phenotypic variances and small confidence intervals indicate that the linkage information between markers and QTLs could easily be used in breeding for heat tolerance