Revisiting Erysiphe magnoliae with morphological and molecular data

Abstract

Erysiphe magnoliae known on Magnolia obovata is a powdery mildew hitherto considered to be native and endemic to Japan. The morphological characteristics of the species have been insufficiently known since its first description in 1951. Fresh samples of this species were collected on M. obovata for the first time in Korea where the species is introduced. Based on the Korean samples, both anamorph and teleomorph of this species are described and illustrated in detail. The inflated base of foot-cells in conidiophores is a unique character not found in the two related species, E. magnifica and E. bulbosa, known on Magnolia spp. The sequences of internal transcribed spacer (ITS) and 28S of ribosomal DNA obtained from Korean and Japanese samples confirmed the phylogenetic position of E. magnoliae in the section Microsphaera of the genus Erysiphe. A comparison of and a synoptic key to the three species of Erysiphe known on Magnolia spp. are provided.