Phylogenetic relationships of graminicolous downy mildews based on cox2 sequence data

摘要: Graminicolous downy mildews (GDM) are an understudied, yet economically important, group of plant pathogens, which one the major constraints to poaceous crops in tropics and subtropics. Here we present a first molecular phylogeny based on cox2 sequences comprising all genera GDM currently accepted, with both lasting (Graminivora, Poakatesthia, Viennotia) evanescent (Peronosclerospora, Sclerophthora, Sclerospora) sporangiophores. In addition, other mildew as well representative sample oomycete taxa, have been included. It was shown that had long, independent evolutionary history, delineation between Peronosclerospora Sclerospora is correct. Sclerophthora found be particularly divergent taxon nested within paraphyletic Phytophthora, but without support. The results confirm placement Saprolegniomycetidae incorrect. not closely related Pachymetra family Verrucalvaceae, also does belong Saprolegniomycetidae, shows close affinities Peronosporaceae. interspersed throughout Peronosporaceae s lat., suggesting separate for Sclerosporaceae might justified.