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Disease Note.

A Storage Decay of Apple Fruit Caused by Aureobasidium pullulans. D. L. Rist, Department of Plant Pathology, NYS (Geneva) Agricultural Experiment Station, Cornell University's Hudson Valley Laboratory, Highland, NY 12528.. D. A. Rosenberger, Department of Plant Pathology, NYS (Geneva) Agricultural Experiment Station, Cornell University's Hudson Valley Laboratory, Highland, NY 12528. Plant Dis. 79:425. Accepted for publication 13 March 1995. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/PD-79-0425A.

In an experiment in which cv. Empire apples (Malus domestica Borkh.) were wounded and inoculated with Penicillium expansum Link, unusual lesions developed around some of the wounds when the fruit were stored at 2.2 C for 3 wk. The lesions generally appeared as distinct, coal-black rings around the wounds and within the larger, caramel-colored lesions induced by P. expansum. These rings were firm compared with the soft decay caused by P. expansum. In a few instances, bruises in apples that were contiguous with the wounds but not visibly decayed by P. expansum also became blackened, but to a lesser degree than in (he rings Dark hyphae were visible in the blackened tissues when squash mounts were viewed at 400x, and were more numerous in the rings than in the bruises. The fungus Aureobasidium pullulans (de Bary) G, Arnaud (1) was consistently isolated from both the rings and bruises. In a second experiment, P. expansum was not involved but an isolate of A pullulans was used to inoculate wounds in Empire apples and black lesions again developed around the wounds. Aureobasidium pullulans was reisolated from these lesions. Aureobasidium pullulans is common on leaf surfaces and can occur as an endophyte in apple leaves (2), but previously has not been reported to infect apple fruit. The fruit in both experiments described here had been stored at 2.2 C for 3 mo prior to the experiments