Polyphasic characterization of four new plant pathogenic Phyllosticta species from China, Japan, and the United States

• Four new Phyllosticta species are introduced based on a polyphasic characterization.
• Distinctions between four new species and other Phyllosticta species are presented.
• Host association is proved to be unreliable in Phyllosticta species delimitation.

The black rot disease of Vitis species and other host genera of Vitacease is caused by Phyllosticta ampelicida and allied taxa which is considered to be a species complex. In this paper, we introduce four new species of Phyllosticta, including two from the P. ampelicida complex, based on a polyphasic characterization including disease symptoms and host association, morphology, and molecular phylogeny. The phylogenetic analysis was conducted based on the ribosomal internal transcribed spacer (ITS) region and a combined multi-locus alignment of the ITS, actin (ACT), partial translation elongation factor 1-alpha (TEF-1), and glyceraldehydes 3-phosphate dehydrogenase (GPDH) gene regions. Our study confirms the phylogenetic distinctions of the four new species, as well as their phenotypic differences with known species in the genus.