Diversity of fungi associated with plants growing in geothermal ecosystems and evaluation of their capacities to enhance thermotolerance of host plants

摘要

Diversity and heat-adaptation of endophytic fungi (EF) and rhizospheric fungi associated with plants growing in geothermal ecosystems, Southwest China, as well as their benefit in improving host plant thermotolerances were investigated. A total of 1589 culturable fungi belonging to 38 taxa were isolated, in which Curvularia, Acrophialophora, Penicillium, and Aspergillus were the dominant genera. The Shannon indices of EF and rhizospheric fungi ranged from 1.80 to 2.56 and 0.73 to 2.11, respectively. Phylogenetic analysis indicated that the EF have a close relationship with rhizospheric fungi. However, some fungi exhibited apparently species-specific habitat distribution patterns. Growth temperature tests indicated that 60.22% of the tested isolates were thermotolerant fungi and only 39.78% were mesophiles, and the number of heat-adapted fungi increased with increasing environmental temperatures. The strain G1-29, which was isolated from the roots of Hedyotis diffusa and identified as Curvularia crepinii, ...