Morphology and multi-gene phylogeny reveal three new species of Clonostachys and two combinations of Sesquicillium (Bionectriaceae, Hypocreales) from Xizang, China.

Abstract

Clonostachys and Sesquicillium are genera in Bionectriaceae, and known in sexual perithecial ascomata and hyphomycetous asexual morphs. In their asexual morph, both genera share similar morphology in conidiophores and conidiogenous cell characteristics but differ in the development of conidiophores. The members of Clonostachys are distributed worldwide with the majority occurring in the tropics and the species are commonly reported as soil-borne fungi but also reported as endophytes, epiphytes, and saprotrophs. During a microfungi survey in Xizang, China, six collections of fresh and healthy Ageratinaadenophora and Houttuyniacordata leaves were obtained. The taxonomy of these collections was investigated through a combination of morphological analysis and multigene phylogenetic analysis using Maximum likelihood and Bayesian inference. The newly generated sequences were clustered within Clonostachys and Sesquicillium, showing hyphomycetes asexual morph. The results revealed three new Clonostachys species viz, Clonostachyslinzhiensis, C.motuoensis, and C.yadongensis. This research sheds light on the overlooked fungal diversity in Xizang, China, expanding the known fungal biodiversity in the region. Additionally, two new combinations, Sesquicilliumaquaticum and S.shanghaiense for C.aquatica and C.shanghaiensis, and one synonymy, C.viticola for C.swietenia are established, respectively.