ENDOCHITINASE AND EXOCHITINASE ACTIVITY IN KIWIFRUIT INFECTED WITH BOTRYTIS-CINEREA

Endo- and exochitinase activities were determined in autoclaved leaves , live leaves, and fruit of kiwifruit (Actinidia deliciosa var. delici osa cv. Hayward [A. Chev.]Liang and Ferguson) following infection with Botrytis cinerea (Pers.). Appreciable endochitinase activity was foun d in healthy and diseased leaves and fruit at harvest and after cool-s torage, but was absent in plant tissue killed by autoclaving. Later ha rvested fruit produced more endochitinase activity in storage than did early harvested fruit. Exochitinase activity was only associated with diseased tissue, and was present in diseased autoclaved leaves. The r esults suggest that endochitinase activity originates from the plant w hilst exochitinase is associated with the pathogen. The significance o f these findings is discussed.