'Plant Breeding: Sustaining the Future' Abstracts of the XVIth EUCARPIA Congress, Edinburgh, Scotland, 10-14 September 2001 A STUDY OF THE PARENTAGE OF THE WINEGRAPE CULTIVAR PLAVAC MALI (VITIS VINIFERA L.) I. PEJIĆ, E. MALETIĆ, J. PILIJAC, G.S. DANGL, J.K. KONTIĆ, N. MIROŠEVIĆ, C.P. MEREDITH Faculty of Agriculture, University of Zagreb, Croatia

It is known that many wine cultivars have arisen from natural crosses. We have taken particular interest in Croatian native cultivars with physiologically female flowers, such as Grk, Barjanka, Bratkovina and Cetinka, and cultivars like Plavac mali and Plavina that could have served as their pollutants. We hypothesise that the island of Korčula might have been a particular rich source for the emergence of new cultivars because it has favourable climate for grapevines, is geographically isolated, has a long winemaking tradition (written evidence from 4^th century BC), and was historically an important crossroads between Greece, Rome and Venice. The above mentioned cultivars have been grown on Korčula for centuries. We analysed 19 cultivars from the southern part of Croatia (primarily Korčula) at 25 SR loci and compared them to over 300 cultivars in the UC Davis database, which includes some Italian cultivars. Genotypes at all loci are consistent with Plavac mali being the progeny of Zinfandel and an unnamed Dalmatian cultivar (misnamed in a collection as Plavac mali). A probability analysis of this parentage will be presented. The SSR genotypes at all loci also support a parent of offspring relationship between Zinfandel and the Dalmatian cultivars Grk, Plavina and Vranac, thus providing additional genetic evidence for the Dalmatian origin of Zinfandel.