Multilocus phylogeny, morphology and taxonomy of Microdochium (Microdochiaceae): insights into evolutionary divergence times and historical biogeography

Microdochiaceae includes many saprobic, endophytic, or pathogenic species, commonly found on plant leaves, seeds, and in soil. Based on samples from four provinces (Fujian, Guangdong, Guangxi, and Hainan) in China, we explored the species diversity, phylogeny, divergence times, and ancestral distribution-determining traits of Microdochium. Morphological and multi-gene (ITS, LSU, rpb 2, and tub 2) phylogenetic analyses revealed eight new species, three new host records, one new geographical record, and one new combination.

The divergence of Microdochium emerged with a mean crown age of 49.5 Mya [95 % HPD of 38.8–61.2 Mya], which occurred in the Paleogene period. Reconstructing ancestral state in phylogenies (RASP) using the Bayesian Binary Markov chain Monte Carlo (BBM) method to reconstruct the historical biogeography for the genus Microdochium indicated that the genus most likely originated in Asia. This study not only advances our understanding of species diversity within Microdochium, but also lays the groundwork for Microdochium evolutionary research.