A Strategy to Identify Probes that Detect a High Degree of Polymorphism in Bread Wheat

Although the genetic linkage map of Trltlcum tauschil, the D-genome progenitor of wheat is available, Its use for linkage analysis of hexaploid wheat chromosome regions is hampered by the lack of polymorphism in wheat. Here we describe a strategy to identify probes that detect a high degree of polymorphism in wheat. The strategy involves the use of DNA probes that detect null alleles. About 16% of the Pstl genomic clones from Tritlcum tauschil detect null alleles in the species. The probes that detect null alleles reveal high degree of polymorphism among hexaploid wheat cultivars. The probes selected following this strategy are expected to detect null alleles throughout the tribe Triticeae, therefore, reveal high degree of polymorphism.