Premium
Mining wild barley for powdery mildew resistance
Author(s) -
Ames N.,
Dreiseitl A.,
Steffenson B. J.,
Muehlbauer G. J.
Publication year - 2015
Publication title -
plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.928
H-Index - 85
eISSN - 1365-3059
pISSN - 0032-0862
DOI - 10.1111/ppa.12384
Subject(s) - powdery mildew , blumeria graminis , biology , hordeum vulgare , plant disease resistance , quantitative trait locus , mildew , hordeum , botany , gene , horticulture , genetics , poaceae
Powdery mildew, caused by Blumeria graminis f. sp. hordei (Bgh), is a worldwide disease problem on barley ( Hordeum vulgare ) with potentially severe impact on yield. Historically, resistance genes have been identified chiefly from cultivated lines and landraces; however, wild barley ( H. vulgare subsp. spontaneum ) accessions have proven to be extraordinarily rich sources of powdery mildew resistance. This study describes the characterization of a collection of 316 wild barley accessions, known as the Wild Barley Diversity Collection ( WBDC ), for resistance to powdery mildew and the genetic location of powdery mildew resistance loci. The WBDC was phenotyped for reaction to 40 different Bgh isolates at the seedling stage and genotyped with 10 508 molecular markers. Accessions resistant to all 40 isolates of Bgh were not found; however, three accessions (WBDC 053, 085 and 089) exhibited resistance to 38 of the isolates. Gene postulation analyses revealed that many accessions, while resistant, contained none of the 12 genes present in the Pallas near‐isogenic lines Mla1 , Mla3 , Mla6 , Mla7 , Mla9 , Mla12 , Mla13 , Mlk1 , MlLa , Mlg , Mlat and Ml(Ru2) , suggesting that the accessions carry novel genes or gene combinations. A genome‐wide association study of powdery mildew resistance in the WBDC identified 21 significant marker‐trait associations that resolved into 15 quantitative trait loci. Seven of these loci have not been previously associated with powdery mildew resistance. Taken together, these results demonstrate that the WBDC is a rich source of powdery mildew resistance, and provide genetic tools for incorporating the resistance into barley breeding programmes.