First comprehensive phylogenetic analysis of the genusErysiphe(Erysiphales, Erysiphaceae) I. TheMicrosphaeralineage

Abstract

The genus Erysiphe (including powdery mildew fungi only known as anamorph, Pseudoidium) is the largest genus in the Erysiphaceae and contains more than 50% of all species in this family. Little is known about the phylogenetic structure of this genus. We conducted a comprehensive phylogenetic analysis of the Microsphaera-lineage, a monophyletic group including species of sects. Microsphaera and Erysiphe, using 401 sequences of nuc ITS1-5.8S-ITS2 and the 28S rDNA regions. This analysis gave many small clades delimited by the host plant genus or family. We identified two deep branches, albeit with moderate bootstrap supports, that divided the 401 sequences into three large groups. In addition, we identified four large clades consisting of homogeneous sequences of powdery mildews from a wide range of host plants beyond family level, namely, the E. aquilegiae clade, the E. alphitoides clade, the E. quercicola clade, and the E. trifoliorum s. lat. clade. Isolates from herbaceous plants were mostly situated in the E. aquilegiae clade and in Group III that was located at the most derived position of the Microsphaera-lineage. On the other hand, the basal part of the Microsphaera-lineage was occupied by isolates from woody plants except for E. glycines that was used as an outgroup taxon. This supports our previous hypothesis that tree-parasitic powdery mildews are phylogenetically primitive in the Erysiphaceae in general, and host-shift from trees to herbs occurred many times independently during the evolution of powdery mildews. Molecular clock analyses suggested that the divergence of the Microsphaera-lineage began ca. 20 million years ago in the Miocene Epoch of the Neogene Period.

Powdery mildew on hazelnut (Corylus avellana) caused by Erysiphe corylacearum in Iran

“…A phylogeny inferred based on ITS sequence data obtained in this study together with 26 sequences from GenBank grouped our sequence in a clade composed of E. corylacearum collections from Corylus spp. including one specimen on C. avellana = KY082910.1 from Turkey (Sezer, Dolar, Lucas, Köse, & Gümüş, ), on C. sieboldiana = LC009928 (Japanese hazel) from Japan (Takamatsu, Ito Arakawa, Shiroya, Kiss, & Heluta, ), and two additional specimens on C. heterophylla = KR048061.1, JX880086.1 (Asian hazel) (Figure ). The sequences obtained in this study are available in GenBank with the accession number .…”

Erysiphe alphitoides causes powdery mildew on Eucalyptus gunnii

“…Furthermore, the powdery mildew species on Quercus spp., viz., Erysiphe epigena , Erysiphe hypogena and Erysiphe quercicola were placed in sister clades. Recently, Takamatsu, Ito, Shiroya, Kiss, and Heluta () showed that the E. alphitoides clade phylogenetically includes powdery mildews from a wide range of host plants including Quercus spp. Therefore, the present powdery mildew on E. gunnii was tentatively identified as Erysiphe sp.…”

“…Erysiphe alphitoides is well‐known as oak powdery mildew fungus in Asia and Europe. However, recent studies showed that E. alphitoides also infects other tropical and non‐tropical trees and shrubs, viz., Mangifera indica, Sorbaria sorbifolia and Wisteria sinensis (Takamatsu et al., ). Furthermore, recent molecular phylogenetic studies show that some powdery mildew species have expanded their host ranges, for example Erysiphe hypophylla on Paeonia lutea, Erysiphe magnifica on Nelumbo nucifera and especially E. quercicola on Bauhinia purpurea, Cinnamomum camphora, Durio zibethinus , Murraya paniculata and Nephelium lappaceum (Farr & Rossman, ).…”

Characterization of Erysiphe sp. causing powdery mildew on Saxifraga stolonifera in Korea

“…The robustness of the NJ trees was evaluated with 1000 bootstrap (BS) values. The NJ trees showed that the Korean isolates from S. stolonifera were placed in the E. aquilegiae clade, as defined by Takamatsu et al (2015) on the basis of ITS +28S rDNA data, with 99% and 100% BS value, respectively (Figs. 2 and 3).…”

“…Therefore, further studies with morphological and molecular characterization are necessary to prove the taxonomic status of the species. Takamatsu et al (2015) performed molecular sequence analyses of Pseudoidium sp. on S. stolonifera and showed that the fungus pertains to the E. aquilegiae clade which comprises numerous morphologically defined powdery mildew species with insufficient resolution just based on ITS data.…”