Studies on the biology and occurrence of Ampelomyces quisqualis in the Drawski Landscape Park (NW Poland)

Abstract

In the years 1996-1998, the ccurrence of Ampelomyces quisqualis parasitizing powdery mildews (Erysiphales) affecting plants of 12 permanent plots with nine plant assciations, as well as those of 32 agricultural fields and gardens of the Drawsko Landscape Park in north-western Poland was investigated. The plant associations of the 12 permanent plots were Luzulo pilosae-Fagetum, Stellrio-Carpinetum, Querco roboris-Pinetum, Leucobryo-Pinetum, Ribo nigri-Alnenun, Circaeo-Alnetum, Vaccino ulginosi-Pinetum, Chenopodietea, and Artemisietea. In the laboratory, the morphology of this hyperparasite, its pattern of colonization of powdery mildews as well as the influence of cultural conditions on its growth and sporulation were determined. Of the 57 species of Erysiphales found in Drawsko Landscape Park, A. quisqualis parasitized 14 in three genera. Of them, nine species were for the first time found to be fungal hosts of A. quisqualis in Poland. This hyperparasite preferred the Artemisietea and Chenopodiatea plant associations, as well as plants of agricultural and horticultural areas, i. e., plants of warmer sites compared with the others considered in this study. The media favouring the growth and sporulation of A. quisqualis were Sabouraud agar and potato dextrose agar. The optimal temperature range for both growth and sporulation of A. quisqualis was 20 -25°C.