Submitted to: Journal of Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2002
Publication Date: 6/21/2002
Citation: DUGAN, F.M., LUPIEN, S.L., GROVE, G.G. INCIDENCE, AGRESSIVENESS AND IN PLANTA INTERACTIONS OF BOTRYTIS CINEREA ANDOTHER FILAMENTOUS FUNGI QUIESCENT IN GRAPE BERRIES AND DORMANT BUDS IN CENTRAL WASHINGTON STATE. JOURNAL OF PHYTOPATHOLOGY. 2002. v. 150. p. 375-381. Interpretive Summary: It has been previously established that the causal agent of bunch rot of grapes, Botrytis cinerea, can exist internally in non- symptomatic grape berries and dormant buds. The extent to which this occurs is significant for the epidemiology of bunch rot. The extent of colonization of non-symptomatic berries and buds by fungi has never been determined for grapes grown in the prime vineyard country of south-central Washington state, nor have the various fungi responsible for this colonization in these vineyards been identified and characterized. This study quantifies the incidence of infection of grape berries and dormant buds by fungi; quantifies the relative aggressiveness of the major fungal species involved with regard to rotting of grape berries; and demonstrates that prior occupation of wound sites by common vineyard fungi retards the advance of rot caused by Botrytis cinerea. On the basis of their findings, the authors present the hypothesis that niche competition from common vineyard fungi may diminish bunch rot in south-central Washington.
Technical Abstract: Recovery of quiescent filamentous fungi from non-symptomatic grape berries and dormant buds demonstrated dominance of Alternaria, Aureobasidium, Cladosporium, Ulocladium and other dematiaceous hyphomycetes. Up to 78% of berries contained fungi prior to harvest. Botrytis cinerea was recovered from 0.2-0.5% of surface-disinfested berries just subsequent to fruit set, and 1.6-4.8% of surface- disinfested, over-wintered dormant buds. In laboratory inoculations of mature grape berries with strains of Alternaria, Aureobasidium, Cladosporium, Ulocladium and Botrytis, only the latter was aggressive in rotting berry fruits. Inoculations with B. cinerea alone and in combination with strains of Alternaria, Aureobasidium, Cladosporium and Ulocladium recovered from grape demonstrated that prior occupation of wound sites by the latter fungi resulted in reduced lesion size compared to inoculation with B. cinerea alone.