VEGETATIVE COMPATIBILITY AMONG ISOLATES OF COLLETOTRICHUM-GLOEOSPORIOIDES FROM ALMOND IN ISRAEL

Anthracnose, caused by Colletotrichum gloeosporioides, is the major di sease of almond in Israel. Pathogen attack of young fruit results in f ruit rot and leaf wilting. Seventy isolates of C. gloeosporioides were obtained from affected almond fruits collected at 11 sites during 199 1-2 and 1994. Chlorate-resistant nitrate-nonutilizing (nit) mutants we re generated from each isolate and used in complementation (heterokary on) tests. The formation of complementary stable heterokaryons between mutants from different isolates showed that all the isolates belonged to a single vegetative compatibility group. Representative isolates o f C. gloeosporioides from almond did not form heterokaryons with local isolates of Colletotrichum from anemone and avocado, indicating that the almond isolates constitute a distinct subspecific group within C. gloeosporioides.