Mapping genes for resistance to Puccinia hordei in barley

Six doubled haploid barley populations (Alexis x Sloop, Chebec x Harrington, Arapiles x Franklin, Patty x Tallon, Tallon x Kaputar, and Sloop x Halcyon) and a recombinant inbred population ( WI2875-1 x Alexis) were assessed for response to selected pathotypes of the barley leaf rust pathogen, Puccinia hordei, at the seedling growth stage. Resistance genes were postulated for the parents of each population based on their reaction to selected pathotypes. In most cases, the resistance genes postulated in the cultivars were validated by QTL mapping analyses of the progeny populations. The resistance genes detected and mapped were Rph2, Rph3, Rph4, Rph12, and Rph19. The chromosomal locations of these 5 genes were consistent with previous reports, with Rph2 mapping near to the centromere on the short arm of chromosome 5H, Rph4 mapping to chromosome 1H, Rph12 mapping to the long arm of chromosome 5H, and Rph3 and Rph19 mapping similar to 30 cM apart on the long arm of chromosome 7H.