Zahavi, T., Dept. of Fruit and Vegetable Storage, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel, Dept. of Fruit and Vegetable Storage, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
Droby, S., Dept. of Fruit and Vegetable Storage, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel
Cohen, L., Dept. of Fruit and Vegetable Storage, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel
Weiss, B., Dept. of Fruit and Vegetable Storage, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel
Ben-Arie, R., Dept. of Fruit and Vegetable Storage, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel

Yeast populations were collected from the surface of berries of three grape cultivars during three seasons, from fruit set to maturity. They were studied by RAPD and ap-PCR, each with two primer pairs. In the population, identical isolates were found only rarely on 13 % of the bunches in 1997 and on 58 % of the berries in 1999. From RAPD and ap-PCR, a dendrogram with clusters of similarity was established. Eleven representatives from clusters of the white yeast dendrogram were identified by traditional methods as 10 different yeast species, one of which has not been isolated from grape berry surfaces before. The population size was smaller for Colombard than for Cabernet Sauvignon and Muscat of Alexandria berries.