Paraphoma species associated with Convolvulaceae

Abstract

Substantial difficulties in the morphological identification of phoma-like fungi, including Paraphoma spp., have resulted in poor understanding of the generic and species boundaries in this group of organisms. This study was devoted to the reidentification and taxonomic revision of phoma-like isolates derived from Convolvulaceae leaves collected from different geographical locations in Russia and territories of neighboring countries. The study was based primarily on sequencing phylogenetically informative loci (ITS, LSU, TUB, and RPB2) and on traditional morphological approaches. The resulting phylogenetic tree revealed three well-supported monophyletic clades, corresponding to three Paraphoma species. The new species Paraphoma melnikiae Gomzhina M. M. & Gasich E. L. was described, and a new taxonomic combination, Paraphoma convolvuli (Dearn. & House) Gomzhina M. M. & Gasich E. L., was established for Stagonospora convolvuli. Several isolates were preliminarily identified as Paraphoma cf. convolvuli and are likely new species of the genus Paraphoma, but this requires further verification.