Phytopythium niubeiliangense sp. nov., a novel species of Phytopythium from warm-temperate forest of China

The Oomycetes are well-known for many important pathogenic species, such as Phytophthora and Pythium species. In this study, two isolates, including a non-papillate, homothallic Phytophthora strain and another papillate, asexual Phytopythium strain, collected from subtropical island of Japan and warm-temperate forest of China respectively, were described. The two strains could not be completely assigned to any existing taxon and were characterized through morphological studies and multi-gene phylogenetic analyses. Additionally, the mitochondrial genome of the new Phytophthora strain was sequenced and annotated, revealing a distinct gene arrangement when compared with related Phytophthora species. Therefore, based on the unique morphological characteristics and taxonomic status, the two strains were described here as two new species formally designated as Phytophthora umbellatus sp. nov. and Phytopythium niubeiliangense sp. nov., respectively. Detailed micro-morphological descriptions, illustrations, and DNA molecular data are provided to confirm their taxonomic placements.