Novel Pestalotiopsis that causes gray spot disease of Polygonatum cyrtonema Hua in Hunan Province of China.

Abstract

Polygonatum cyrtonema Hua is a perennial herb of the Asparagaceae family that is used for both dietary and medicinal purposes in China. In September 2019, a new leaf spot disease on Po. cyrtonema was detected which is currently widespread in Huaihua, Hunan Province, China. Pathogenic fungi were isolated and purified from samples of diseased tissue that were collected for morphological and molecular phylogenetic studies. The pathogen was identified using multi-locus (ITS, TEF-1, TUB2) phylogenies, as well as morphological characters, and was found to be clustered but separately divergent from species of Pestalotiopsis. However, there were significant morphological differences between the pathogen and similar species. The pathogen was finally identified as a new species that was designated Pestalotiopsis xuefengensis. This is the first report of P. xuefengensis serving as the causal agent of gray leaf spot on Po. cyrtonema. This study will provide useful information for the diagnosis and management of this disease.