Taxonomy and phylogeny of the Erysiphe lonicerae complex ( Helotiales , Erysiphaceae ) on Lonicera spp

The phylogeny and taxonomy of powdery mildews, belonging to the genus Erysiphe , on Lonicera species throughout the world are examined and discussed. Phylogenetic analyses revealed that sequences retrieved from Erysiphe lonicerae , a widespread powdery mildew species distributed in the Northern Hemisphere on a wide range of Lonicera spp., constitutes a complex of two separate species, viz ., E. lonicerae ( s. str .) and Erysiphe ehrenbergii comb. nov . Erysiphe lonicerae occurs on Lonicera spp. belonging to Lonicera subgen. Lonicera (= subgen. Caprifolium and subgen. Periclymenum ), as well as L. japonica . Erysiphe ehrenbergii comb. nov . occurs on Lonicera spp. of Lonicera subgen. Chamaecerasus . Phylogenetic and morphological analyses have also revealed that Microsphaera caprifoliacearum (≡ Erysiphe caprifoliacearum ) should be reduced to synonymy with E. lonicerae ( s. str. ). Additionally, Erysiphe lonicerina sp. nov . on Lonicera japonica in Japan is described and the new name Erysiphe flexibilis , based on Microsphaera lonicerae var. flexuosa , is introduced. The phylogeny of Erysiphe ehrenbergii and E. lonicerae as well as other Erysiphe species on honeysuckle is discussed, and a survey of all species, including a key to the species concerned, is provided.