Abstract
Production of grape varieties of high quality, at the same time resistant to fungal diseases is one of the most important goals of grape breeding. The aim of our planned project is to identify plant alleles responsible for resistance against downy and powdery mildew (Plasmopara viticola and Uncinula necator) with molecular markers. Molecular markers can enhance the mapping and cloning of these genes, help to find major and minor QTL-s of resistance genes. Based on microsatellite markers the characterisation of biodiversity of old and registered grapevine varieties has been started and is going to be continued, on the one hand applying SSR markers (SSR: Simple Sequence Repeat) linked to fungal resistance genes deriving from Muscadinia rotundifolia (Powdery mildew: Run1-Uncinula necator, downy mildew: Rpv1: Plasmopara viticola). On the other hand, new markers (RGA: Resistance Gene Analogs; CAPS; Cleaved Amplified Polymorphic sequences; EST; Expressed Sequence Tags) will be tested to determine linkage between resistance genes and the markers, providing the localisation of resistance QTL-s. For this purpose not only fungus resistant or susceptible cultivars will be analysed, but hybrid mapping populations, deriving from different intra- and interspecific crosses of Vitis vinifera with Muscadinia rotundifolia, Vitis amurensis. In these combinations several new cultivars of high quality were involved, which derive from Franco-American hybrids carrying resistance against fungal diseases. Varieties of Middle-Asian origin such as ’Dzandzal Kara’ and ’Kismis vatkana’ are highly resistant to powdery mildew. Molecular basis of powdery mildew of ’Kismis vatkana’ and its hybrid will also be examined in the frame of this project.
Hungary