Abstract

The host specialization of Erysiphe cichoracearum from skeleton weed, Chondrilla juncea, was studied in Europe. Plant species comprising a number of cichoriaceous plants closely related to Chondrilla, and cultivated plants belonging to 23 families particularly including the cultivated Compositae, Cucurbitaceae, Solanaceae, and Leguminosae, on which forms of this fungus have been recorded, were inoculated with conidia of the mildew. Moreover, three cultivars of all cultivated species recorded as hosts of any form of E. cichoracearum were tested. The powdery mildew from C. juncea did not develop on any of these plants.