Identification of resistance to tan spot (Pyrenophora tritici-repentis) in Hordeum chilense and its expression in its amphiploids with diploid, tetraploid and hexaploid Triticum species

摘要

Hordeum chilense Roem. et Schult. is a native South American diploid wild barley with high potential for cereal breeding purposes, given its high crossability with other members of the Triticeae tribe. Amphiploids have been obtained from crosses of H. chilense with diploid, tetraploid and hexaploid Triticum species that have been postulated as a potential new crop named tritordeum or as bridges to transfer useful genes to cultivated cereals. In this paper we describe resistance in H. chilense to tan spot disease, caused by Pyrenophora tritici-repentis (Died.) Drechs. Twenty-two tritordeum lines together with their wheat and H. chilense parents were inoculated with three different races of P. tritici-repentis. While all H. chilense accessions studied were resistant, wheat accessions response ranged from susceptibility to high resistance. The two tetraploid tritordeum accessions studied were very resistant as was their T. tauschii (Coss.) Schmalh. parent line. Hexa- and octoploid tritordeum accessions were more resistant than their parental wheat accessions. Consequently, H. chilense appears as a good reservoir of resistance to P. tritici-repentis, accessible for wheat breeding. © 2012 Blackwell Verlag GmbH.