title: First comprehensive phylogenetic analysis of the genus Erysiphe (Erysiphales, Erysiphaceae) II: the Uncinula lineage.
abstract: Phylogenetic relationships of the Uncinula lineage, which is the basal group in the genus Erysiphe, were investigated with 167 sequences of nuc ITS1-5. 8S-ITS2 and the 28S rDNA regions. Backbone tree analyses with six datasets and two tree-constructing methods revealed that the Uncinula lineage is divided into seven distinct clades. Clades 1-5 each contained a representative powdery mildew species, namely E. australiana in Clade 1, E. liquidambaris in Clade 2, E. adunca in Clade 3, E. fraxinicola in Clade 4 and E. actinidiae in Clade 5. Clade 6 comprises 71 sequences including the Microsphaera lineage and 17 species of the Uncinula lineage, such as E. carpinicola, E. carpinilaxiflorae, E. miyabei, E. glycines and E. necator. Topology tests supported the Microsphaera lineage forming a monophyletic clade in Clade 6, suggesting that Microsphaera-type appendages appeared only once in this clade to diverge into the Microsphaera lineage. Clade 7 consists of 72 sequences containing 30 species, including species of sects. Californiomyces and Typhulochaeta, four species from Nothofagus, species of sect. Erysiphe parasitising herbaceous plants belonging to the Asteraceae, Rosaceae and Saxifragaceae. Molecular clock analysis suggests that the major seven clades appeared 50-30 million years ago (Ma) in the Paleogene Period. The Microsphaera lineage may have split from the Uncinula lineage at the boundary of the Paleogene and Neogene, when appendages with dichotomously branched tips appeared. The clade of the species on Nothofagus split from the northern hemisphere species about 20-10 million years ago (Ma) in the Miocene Epoch, and host-shift from trees to herbs also might have occurred in this period.
authors.affiliation: Department of Bioresources, Graduate School, Mie University, 1577 Kurima-Machiya, Tsu 514-8507, Japan takamatu@bio.mie-u.ac.jp.
authors.forename: Susumu
authors.initials: S
authors.lastname: Takamatsu
authors.affiliation: Department of Bioresources, Graduate School, Mie University, 1577 Kurima-Machiya, Tsu 514-8507, Japan.
authors.forename: Hanako
authors.initials: H
authors.lastname: Ito Arakawa
authors.affiliation: Department of Bioresources, Graduate School, Mie University, 1577 Kurima-Machiya, Tsu 514-8507, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Shiroya
authors.affiliation: Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences (MTA), 1525 Budapest, P.O. Box 102, Hungary.
authors.forename: Levente
authors.initials: L
authors.lastname: Kiss
authors.affiliation: M.G. Kholodny Institute of Botany of the National Academy of Sciences of Ukraine, 2 Tereshchenkivska Street, Kiev, 01601, Ukraine.
authors.forename: Vasyl
authors.initials: V
authors.lastname: Heluta
mesh_terms: D001203:Ascomycota / Q000235:genetics*; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology; D010944:Plants / Q000382:microbiology; D012331:RNA, Fungal / Q000235:genetics; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D013045:Species Specificity
chemical_list: D012331:RNA, Fungal; D012339:RNA, Ribosomal, 28S
keywords: 28S rDNA; ITS; appendage; host relationship; molecular clock; powdery mildew