Early evolution of endoparasitic group in powdery mildews: molecular phylogeny suggests missing link between Phyllactinia and Leveillula.
Of the 17 genera of the Erysiphaceae, only four genera (viz. Leveillula, Phyllactinia, Pleochaeta and Queirozia) exhibit (partly) endoparasitism. To investigate early evolution of this endoparasitic nature, we performed molecular phylogenetic analyses of powdery mildews belonging to the tribe Phyllactinieae collected in North and South America. The most ancestral taxa in the tribe Phyllactinieae belong to the Pleochaeta/Queirozia group, from which the genus Phyllactinia was derived. Finally, the truly endoparasitic genus Leveillula emerged from a part of Phyllactinia The present study showed clear evolutional polarity in the powdery mildews concerned (that is, partly endoparasitic group evolved from ectoparasitic group) and then a truly endoparasitic group emerged from a partly endoparasitic group. In addition, a group with distinctly dimorphic conidia proved to be basal in the Phyllactinieae, and a group without distinctly dimorphic conidia was derived from that group. The present analyses clearly showed that Leveillula derived from a part of the "Basal Phyllactinia group". However, all sister taxa to Leveillula were distributed in North and South America. Because the putative geographic origin of Leveillula is assumed to be Central and Western Asia or the Mediterranean region, we postulate a missing link during the evolution of Leveillula from Phyllactinia Based on the present phylogenetic studies and the new rules of the International Code of Nomenclature for algae, fungi, and plants (McNeill et al. 2012), the following new species and taxonomic re-allocations are proposed: Phyllactinia bougainvilleae sp. nov., Ph. caricae comb. nov., Ph. caricicola comb. nov., Ph. durantae comb. nov., Ph. leveilluloides sp. nov., Ph. obclavata comb. nov., and Ph. papayae comb. nov.
Department of Bioresources, Graduate School, Mie University, 1577 Kurima-machiya, 514-8507 Japan takamatu@bio.mie-u.ac.jp.
Susumu
S
Takamatsu
Department of Bioresources, Graduate School, Mie University, 1577 Kurima-machiya, 514-8507 Japan.
Siska A S
SA
Siahaan
Autonomous University of Aquascalientes, Center of Basic Sciences, Department of Microbiology, Av. Universidad No. 940, Colonia Cd. Universitaria, 20131 Aguascalientes, Ags., Mexico.
Onésimo
O
Moreno-Rico
Faculty of Agrarian Sciences, National University of the Northeast, 3400 Corrientes, Argentina.
Maria G
MG
Cabrera de Álvarez
Martin Luther University, Institute of Biology, Geobotany and Botanical Garden, Herbarium, Neuwerk 21, 06099 Halle (Saale), Germany.
Uwe
U
Braun
D001203:Ascomycota / Q000145:classification* / Q000166:cytology / Q000235:genetics* / Q000302:isolation & purification; D019143:Evolution, Molecular; D008853:Microscopy; D009656:North America; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013020:South America; D013172:Spores, Fungal / Q000166:cytology
Erysiphaceae; Erysiphales; Phyllactinieae; Pleochaeta; Queirozia