Notes on powdery mildews (Erysiphales) in Thailand V. Golovinomyces

Records of Golovinomyces species new to Thailand are described on the hosts Ageratum conyzoides, Bidens pilosa, Dahlia pinnata, D. × hortensis, Helianthus annuus, Lactuca indica, Laggera crispata, Sonchus oleraceus (Asteraceae), Lygisma inflexum (Asclepiadaceae), Myosotis scopioides (Boraginaceae), Coccinia indica, Coccinia grandis (Cucurbitaceae), Vigna umbellata (Fabaceae), Torenia fournieri (Linderniaceae), Plantago major (Plantaginaceae) and Verbena × hybrida (Verbenaceae). The identifications of the particular Golovinomyces species have been performed by means of morphological examinations supplemented by molecular sequence analyses. On the basis of molecular analyses, the powdery mildew on Ocimum tenuiflorum (Lamiaceae) proved to represent a species of its own, which is referred to as Golovinomyces ocimi comb. nov. The application of Oidium ocimi, the basionym of this combination, is determined by lecto- and epitypification. Lygisma inflexum, Laggera crispata and Vigna umbellata are new host records for Golovinomyces worldwide.