Identification and expression of adult plant resistance in barley to powdery mildew (Blumeria graminis f. sp. hordei) in Australia

Barley powdery mildew caused by Blumeria graminis f. sp. hordei is a most devastating disease in Western Australia and elsewhere. The disease has a negative impact on grain yield and quality and, thus, affects its marketability. The detection of pathogen variability has further impacted sustainable barley production. Various isolates have been reported to have broken down the resistance genes present in the upcoming barley cultivars. Because of this there is an increasing importance to identify novel resistances to powdery mildew with its effectiveness across barley growing regions of Australia. A set of 12 lines out of 101, which have originated from Australia, Czech Republic, South America, Sweden, South Africa and CIMMYT/ICARDA, was studied for growth stage responses in which 11 lines were identified to have adult plant resistance (seedling susceptibility). This set was evaluated over 2 years and across five different environments in Western Australia and Tasmania. Majority of the lines are effective across different environments and warrants its characterisation. The set holds a great promise and can broad narrow genetic base of current barley cultivars. This is a first report of identification of adult plant resistance for powdery mildew in barley lines from Australia.