Detection of QTL for bread-making quality in wheat using molecular markers

Abstract

Bread-making quality in wheat (Triticum aestivum) is a complex trait influenced at once by genetic factors and environmental conditions. The development of molecular biology technics together with intervarietal genetic maps provide a useful tool for the understanding of complex agronomic traits such as quality. The aim of our study was to identify QTL for bread-making quality using a doubled-haploid lines population issued from a cross between Courtot and Chinese Spring. Three hundred and eighty loci were mapped using a subset of 106 lines and 187 lines were genotyped for the anchor markers of this map. Between 144 and 172 DH lines were grown under field conditions for three consecutive years (1994 and 1995: one replication; 1996 two replications) and between 106 and 163 were submitted to several technological tests. We were thus able to approach the genetic control of quality traits (strength (W), grain hardness and protein content) that were highly contrasted between the two parents. Despite the fact that the D genome was under represented because of a lack of polymorphism, it appeared that an important part of the variation was explained by the QTL located at different loci than those of the storage proteins (glutenins and gliadins), which seemed to play a minor role compared to other regions of the genome. We are now planning to study some of these regions to identify the genes that could be involved in the baking process.