Molecular phylogeny of Nectria species associated with dieback and canker diseases in China, with a new species described

Abstract

Nectria is a wood-inhabiting genus of fungi commonly found in temperate regions of the northern hemisphere, where they are associated with dieback and canker diseases of numerous woody plant hosts. In this study, fungal isolates were collected from 2012 to 2017 from diseased branches or twigs of 19 different host species in China and identified. Their morphological characteristics and multi-locus phylogeny (act, ITS, LSU, rpb2, tef1, and tub2) indicated four distinct lineages with high statistical support, corresponding to four species of Nectria: N. balansae, N. dematiosa, N. pseudotrichia, and N. ulmicola sp. nov. The last is characterized by yellow to orange, or sometimes dark brown, sporodochial conidiomata, which are sessile, and by unbranched or bifurcate conidiophores. This study has clarified the taxonomy of Nectria species associated with canker and dieback symptoms in China.