Phylogenetic relationships and generic affinity ofUncinula septatainferred from nuclear rDNA sequences.

Based on 18S, 5.8S, and 28S rDNA sequences, the phylogenetic position ofUncinula septatawithin the Erysiphales has been inferred. Although appendages of the ascomata are uncinula like, i.e., unbranched with curved-coiled apices,U. septatais situated at the very base of the large Erysiphales cluster, far away from the “pseudoidium clade” (Erysiphe emend., includingMicrosphaeraandUncinula). Morphologically,U. septatadiffers from the species ofErysiphesect.Uncinula(=Uncinula) in having terminal, pluriseptate ascoma appendages, curved ascospores, and the absense of an anamorph. This species is a basal, tree-inhabiting powdery mildew with some additional ancestral characteristics, viz., uncinula-like appendages and 8-spored asci. The new genusParauncinulawithU. septataas the type species is proposed.Uncinula curvispora(=U. septatavar.curvispora) is tentatively maintained as a separate species, which is also assigned toParauncinula. [ABSTRACT FROM AUTHOR]