Notes on Dictyuchus species (Stramenopila, Oomycetes) from Anzali lagoon, Iran

Abstract

Nine Dictyuchus isolates were obtained from floating and decaying twigs and leaves in Anzali lagoon, Anzali County, Guilan province, Iran. They are interestingly distinguished from current Dictyuchus species by the presence of dictyoid and achlyoid type of zoospore discharge, abundant fusiform and spherical gemma, and the absence of any sexual apparatus. In addition, phylogenetic analyses of the internal transcribed spacer (ITS) region of the nuclear rDNA and cytochrome c oxidase subunit I (cox1) gene sequences using Maximum likelihood method indicate its novelty. We preferred not to introduce the isolates as new species due to low number of and sometimes unreliable sequences and lack of type species and suggested to verify Dictyuchus sterilis which has been excluded before. We discussed about taxonomy of the genus in details and provided a revised key to the species. In addition, it was shown that sterility in vitro might be common in this genus.