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.

Morphology and molecular phylogeny of a poorly known species—Erysiphe bulbouncinula (Erysiphaceae) on Koelreuteria paniculata

“…All sequences are divided into 7 clades which are consistent to the results of Takamatsu et al. (2015a), and E. bulbouncinula is located in the clade 7.…”

“…Among the eight ITS sequences, five sequences (MT026701–05) are identical to each other and have three base nucleotide differences from sequence MT026688 and MT026689, and two base differences from sequence MT027918. The BLAST result of the newly obtained ITS (MT026701–05, including the 5.8S rDNA) sequence against the NCBI nucleotide database showed highest identity of 89% with Erysiphe pseudogracilis (LC271392) which belongs to clade 7 in the Uncinula lineage based on the results in Takamatsu, Ito (Arakawa), H., Shiroya, Y., Kiss, L., and Heluta, V. (2015a).…”

“…Secondly, we constructed a phylogenetic tree using a combined data set of ITS and 28S rDNA sequences of the Uncinula lineage following the results of Takamatsu et al. (2015a) (see Figure S1) to investigate phylogenetic placement of E. bulbouncinula in the genus Erysiphe ( Uncinula lineage). The sequences of Phyllactinia moricola , Leveillula taurica , Golovinomyces circumfusus and G. orontii were used as an outgroup taxon.…”

Erysiphe deutziae causing powdery mildew on Deutzia parviflora var. amurensis in China

“…For phylogenetic analysis against ITS rDNA accessions deposited at GenBank, the two newly obtained sequences were aligned with three sequences of this species and 24 sequences from morphological similar species; two sequences from E . glycines served as an outgroup (Takamatsu, Ito Arakawa, Shiroya, Kiss, & Heluta, ). These data consisted of 31 sequences with 586 characters, of which 158 (27.0%) characters were variable and 140 (23.9%) characters were informative for parsimony analysis.…”

Host genetics and environment shape fungal pathogen incidence on a foundation forest tree species, Populus tremuloides

“…of strains from the willow (Salix) subclade of the E. adunca complex(Takamatsu et al 2015), 163 and even less similar to sequences of strains of powdery mildew pathogens from other tree hosts.…”