665 Breeding Strategy for the Introgression of Disease Resistance Genes into European Grapevine E. Peterlunger, G. Di Gaspero, G. Cipriani, P. Sivilotti, L. Zulini, M.T. Marrazzo, D. Andreetta, R. Testolin Dept. Produzione vegetale e tecnologie agrarie, University of Udine Via delle scienze 208, 33100 Udine, Italy Keywords: Vitis, genetics, breeding, disease resistance, linkage map, molecular markers, RGA, sustainable agriculture Abstract A breeding program aiming to introgress genes of resistance to several diseases, such as downy mildew, powdery mildew and Botrytis into the European grapevine has been initiated in 1998 at the University of Udine. Susceptible (S) and resistant (R) grapevine breeding lines were crossed according to a mating plan designed to produce S x R and R x R families. The R-lines included genotypes carrying resistances from American and/or Asian species. For each class of cross, several genotypes were crossed in all combinations irrespective of the way and without reciprocals. Selfing of S- and R-lines was also included. Twenty-eight crosses have already been made, the family size ranging from a few to 136 individuals. At the same time, molecular markers (anonymous SSRs and SNPs derived from Resistance Gene Analogs) were isolated to produce a transportable and functional linkage map. Beside 371 SSRs isolated together with other partners of the Vitis Microsatellite Consortium, further 101 new SSRs from AC-repeat enriched libraries were isolated. New libraries enriched in di- and tri-nucleotide repeats have been produced and isolation of new SSRs is underway. SNPs are being produced from 80 RGAs isolated in grape up to now. Through recurrent cycles of assessment of classes of phenotypic resistance/susceptibility and QTL analysis, we expect to elucidate the genetic control of resistance to several diseases and to identify genes/QTLs, which control such diseases. In the present paper, we give an overview of the whole research plan, the activities carried out, the results achieved in the first three years, and the strategy adopted to develop new grapevine cultivars suitable for the Friuli- Venezia Giulia region. INTRODUCTION Downy mildew (Plasmopara viticola), powdery mildew (Uncinula necator f. c. Oidium tuckerii) and grey mold (Botryotinia fuckeliana f. c. Botrytis cinerea) are severe grape diseases, which require many sprays in cold-temperate climates. The European grapevine cultivars lack native resistances to these diseases (Alleweldt et al. 1990, Reisch and Pratt 1996) and breeding programs, initiated world-wide several decades ago, has resorted to sources of resistance carried by American and Asian species (Boubals 1959, Boubals 1961, Bouquet et al. 1981, Staudt and Kassemeyer 1995, Staudt 1997, Kozma 2000, Pauquet et al 2001). We initiated in 1998 at the University of Udine a breeding program aiming to introgress disease resistances brought by European advanced breeding lines into international and local susceptible grape cultivars. The mating design included also wild resistant genotypes as parents for better characterising the genetic sources of phenotypic resistances. This paper describes the breeding activities, the results achieved and the perspectives. Proc. VIII th IC on Grape Eds: E. Hajdu & É.Borbás Acta Hort 603, ISHS 2003