RESOLUTION OIV-VITI 515-2013

STABILITY OF DISEASE RESISTANCE IN NEW CULTIVARS BY COMBINING RESISTANCE LOCI

THE GENERAL ASSEMBLY,

At the proposal of Commission I “Viticulture”,

IN VIEW OF the progress achieved by the work carried out within the “Genetic Resources and Vine Selection” expert group, and in reference to points G.2 and G.4 of the OIV Strategic Plan 2012-2014,

CONSIDERING that fungus diseases, and especially downy and powdery mildew, belong to the most serious diseases of the vine all over the world, requiring significant plant protection measures to be taken,

CONSIDERING the huge efforts of vine breeders in various countries to introgress downy and powdery mildew resistance characteristics from the gene pool of wild species into traditional cultivars,

CONSIDERING the potential risk of the effect of individual resistance loci being overcome by the development of more aggressive strains of the pathogen,

CONSIDERING the tremendous progress achieved in recent years in grapevine genetics by identifying different sources of resistance located in different genomic regions,

CONSIDERING newly developed tools like Marker Assisted Selection (MAS) which allows the tracing of segregation patterns of genomic regions coding important traits,

CONSIDERING the potential of these tools for effectively combining different resistance loci,

RECOMMENDS obtaining and developing new cultivars which carry multiple resistance loci or have a synergistic effect against one pathogen in order to:

• Increase stability of resistance
• Lower the risk of selection and of development of more aggressive pathogen strains
• Improve sustainability of viticulture

RECOMMENDS applying appropriate plant protection measures in order to provide supplemental support with a view to managing the genetic resistance of cultivars in a sustainable manner.