Relative tolerances of wild and cultivated barleys to infection by Blumeria graminis f.sp. hordei (syn. Erysiphe graminis f.sp. hordei)

The relative tolerances of two lines of wild barley (Hordeum spontaneum), B19909 and I-17-40 and one cultivated barley (Hordeum vulgare), cv. Prisma infected by Blumeria graminis f.sp. hordei (syn. Erysiphe graminis f.sp. hordei) were investigated by growth analysis. Mildew development was assessed as percentage leaf area colonised, and by numbers of conidia produced. At all stages of plant growth, the percentage leaf area colonised by the mildew was slightly higher on the wild line B19909 than on cv. Prisma and much more than on the wild line I-17-40. When mildew was measured as conidial production, line B19909 was found to support more fungal biomass than cv. Prisma and cv. Prisma much more than line I-17-40.