Dark septate endophytes colonizing the roots of non-mycorrhizal' plants in a mine tailing pond and in a relatively undisturbed environment, Southwest China

Dark septate endophytes (DSEs), one of the most common fungal colonizers of roots, are considered to overlap in function with mycorrhizal fungi. However, there is little knowledge on the distribution and identity of DSEs in non-mycorrhizal' plants. In the current study, colonization and diversity of DSEs colonizing the roots of eight typically non-mycorrhizal' families were assessed. In total, 120 root samples of 31 plant species were all colonized by DSEs. Intensity of DSE colonization varied greatly among different plant species, with a range of 0.56-47.56%, 8.13% on average. Cladosporium, Cyphellophora and Phialophora were the dominant genera, with a relative abundance of more than 60% over a total of 90 isolates. Our results showed that diverse DSE species colonized the roots of non-mycorrhizal' plants, especially they were more common in degraded mine tailings than in the undisturbed site, but their integral roles to the functional roots are in need of further experimental demonstration.