Inheritance of Resistance to Powdery Mildew (Blumeria graminis f.sp. hordei) in Selections from Moroccan Landraces of Barley

Abstract

Powdery mildew caused by the pathogen Blumeria graminis (DC.) Golovin ex Speer f. sp. hordei Em. Marchai is one of the most serious foliar diseases of barley (Hordeum vulgare L.) in Europe. This study was conducted to determine the number of genes, the types of genes action and the gene loci conferring resistance to powdery mildew in two selections E 1059-1-1, E 1067-1-2. These lines were selected from barley landraces collected were collected during expedition organized by Warsaw Agricultural University SGGW-AR in Southern Morocco (Agadir Province). Two types of crosses were made: (1) the lines were crossed with the susceptible cultivar Pallas, (2) the lines were crossed with six Pallas isolines with Mla3 (isoline P2), Mla12 (isoline P10), Mlp (isoline P19), Mlat (isoline P20), Mlg (isoline P21) and mlo5 (isoline P22) genes for resistance. The parents, F1, F2, F3 were evaluated for the powdery mildew resistance with isolate R303.1. On the basis of segregation ratios it was found that resistance in tested lines was determine by a single dominant gene at the locus Mla. Results are compared with previous study in which the presence of genes in Mla locus was postulated based on testing of these lines with 30 differential isolates of powdery mildew. The possible use of new identified sources of resistance to powdery mildew was discussed.