Species Diversity of Phaeobotryon Associated with Tree Canker and Dieback Diseases in Xinjiang, China

Abstract

Withered branch disease is a major threat to the health of forest trees, resulting in the death of susceptible branches and even the whole plant. Botryosphaeriaceae members (e.g., Phaeobotryon spp.) are common pathogenic fungi that cause withered branches, canker and dieback disease symptoms in woody plants. This study aimed to identify the Phaeobotryon species inhabiting tree species with canker and dieback symptoms in Xinjiang Uyghur Autonomous Region, China, based on both morphological and phylogenetic approaches. In the current study, branches and twigs showing typical symptoms of canker and dieback were collected from Elaeagnus angustifolia, Juglans regia, Malus pumila, Malus ‘Royalty’, Prunus armeniaca (wild apricot) and Rhus typhina growing on Tianshan Mountain in the Xinjiang Uygur Autonomous Region of China. Phaeobotryon species isolated from these samples were characterized based on methods of morphology and molecular phylogeny. As a result, two species were identified: P. rhoinum and a new species Phaeobotryon mali sp. nov. Here, we provide a description and illustrations of this new species for science.