EVALUATION OF SCAB AND POWDERY MILDEW RESISTANCE OF APPLE GERMPLASM COLECTTED AT RIFG PITESTI

Abstract

The rising incidence of biotic and abiotic stresses makes commercial fruit production increasingly difficult in Europe, especially apple orchards which are affected by fungal diseases, like scab and powdery mildew, caused by Venturia inaequalis Cooke Winter and Podosphaera leucotricha Ellis & Everh. Salmon. Releasing and planting of apple resistant cultivars is a promising strategy. A set of 527 apple cultivars from the apple gene bank collected at Research Institute for Fruit Growing (RIFG) Pitești was evaluated for the incidence of scab (on leaves and fruits) and powdery mildew (on leaves and top shoots) in three consecutive years (2018, 2019 and 2020). Phenotypic results were compared to data reported at the evaluation made in 2006. Unfortunately, the incidence of both scab and powdery mildew increased significantly in the last years. In 2021, 48 Romanian apple cultivars were analyzed with molecular markers linked to Rvi2, Rvi4, Rvi5, Rvi6, Rvi8 and Plw. The markers linked to Rvi6 was detected in 31 cultivars. Alleles linked to Plw were expressed from three cultivars. The information on resistance / susceptibility of apple genetic resources towards economically important diseases is important for breeding. Using a systematic screening of the apple cultivar collection, several cultivars with high value for resistance breeding and sustainable growing were identified.