Morphological and phylogenetic analyses revealed a new species of Erysiphe sect. Microsphaera on Lonicera in China

The powdery mildew species Erysiphe lonicericola, collected in China on Lonicera rupicola, is described on the basis of its morphological characteristics and analyses of the internal transcribed spacer (ITS) region of the ribosomal DNA, which suggested the involvement of a new species. Light and scanning electron microscopy observations indicated that this species is morphologically clearly distinguished from Erysiphe chifengensis and E. ehrenbergii, two similar species on other hosts of the Caprifoliaceae. It could be demonstrated that the L. rupicola powdery mildew is genetically different from all other Erysiphe species, but the phylogenetic affinity of the new species could not be clarified. The bootstrap support values of the corresponding deeper branches are too low.