First Report of Powdery Mildew Caused by Golovinomyces spadiceus on Okra in the United States

Multi-locus phylogeny and taxonomy of an unresolved, heterogeneous species complex within the genus Golovinomyces (Ascomycota, Erysiphales), including G. ambrosiae, G. circumfusus and G. spadiceus

“…Subram., Hyphomycetes (New Delhi): 835 (1971). [19], Khodaparast [52], Arzanlou et al, [53], Meeboon et al, ([11], p. 212), Moparthi et al, [29,54], Trigano et al, [28], Braun et al, [13]. Material examined: additional collections used for molecular analyses (see Table 1 Description: Mycelium amphigenous, but sometimes also caulicolous, thin, white, effuse or in distinct patches, persistent on the upper leaf surface and on stems, less conspicuous and often evanescent on lower surface; hyphae branched mostly at right angles, hyaline, smooth or almost so, 3-9 μm wide; hyphal appressoria usually solitary, slightly to distinctly nipple-shaped, 3-7 μm diam.…”

“…The morphological differences used to differentiate the species include above all, much broader conidia and dimorphic germ tubes belonging to the longitubus pattern within the Euoidium type of conidial germination in G. ambrosiae than in G. spadiceus [1]. Additional research has found G. spadiceus to be extremely plurivorous, occurring on hosts of the Heliantheae and other tribes of Asteraceae, e.g., Aster and Chrysanthemum [19], Chrysogonum [28], as well hosts of various other plant families, including Abelmoschus (Malvaceae) [29], Crotalaria (Fabaceae) [13], Persicaria (Polygonaceae) [11,13,30], Solanum (Solanaceae) [13], and Verbena (Verbenaceae) [13]. The taxonomic interpretation of the inclusion of a sequence obtained from a Japanese collection of powdery mildew on Eupatorium chinense in lineage III [19] caused an additional problem and raised the question whether the name G. circumfusus, originally described from Europe on Eupatorium cannabinum, is included in this species complex.…”