Genetic Diversity of Barley Accessions from Ethiopia for Powdery Mildew Resistance

In laboratory experiments, 925 Ethiopian barley accessions were studied for juvenile resistance to the northwest population of powdery mildew causative agent Blumeria graminis (DC.) Golovin ex Speer f. sp. hordei Marchal. Based on phenotypic screening, the 27 accessions resistant to the pathogen were selected and 47 forms were heterogenous for the studied character. The resistant and susceptible plants of the examined accessions were analyzed with the use of molecular markers developed for identification of the mlo11 allele. Fifteen accessions carrying the mlo11 allele, which determines durable resistance of most modern barley varieties to powdery mildew, were revealed. The accessions differed by the resistance expression that can be explained both by the manifestation of other resistance genes, which are inadequate to the mlo11, and also by the presence of different mlo11 allelic variants in the genotypes of the selected accessions. The resistance to B. graminis of the other 59 forms is controlled by the effective genes that are different from mlo11.