Molecular analysis of resistance genes against phylloxera, antracnosis and crown gall disease in a collection of different grapevine accessions

Abstract

In the year 2012 the Laimburg Research Centre, in collaboration with the Autonomous Province of Bolzano and the private platform InnoVitis in Marlengo, has started a project called RebSelect with the aim to characterise a collection of about 150 grapevine accessions of particular interest for the presence of resistance genes to fungal and other diseases. The objectives of the project are the creation of a grape genetic bank by molecular methods (MAS, marker assisted selection), to identify resistance genes to various diseases in this collection and to select resistant plants to be used as parents in the next crossings. This will be helpful for the establishment of new resistant varieties with high quality. In this thesis, we have focused on genomic regions related to the resistance to phylloxera (Viteus vitifoliae), crown gall (Agrobacterium vitis) and anthrachnose (Elsinoë ampelina), utilizing microsatellite or SCAR markers already published in the literature. It is shown that the markers suitable for the MAS and usable for the identification of resistant varieties (used subsequently for further crossings for the purposes of genetic improvement) are those for Rdv1, associated with resistance to phylloxera. For the resistance to crown gall disease (Rcg1) the results are controversial, making these markers not exploitable for MAS: a fine mapping of the designated area will be necessary to search for markers closer to Rcg1. Finally, the only marker that appeared to be associated to resistance against anthracnose needs to be discarded due to false positive results for all analysed accessions.