The Janzen-Connell hypothesis proposed plants interacting with host-specific natural enemies explained the coexistence of the large number of tree species, in which fungi are important components. In addition, both abiotic and biotic factors can affect plant-fungi communication, plant growth and species-specific effect. However, fungi composition in plant roots, the host specificity, and the direct-indirect influences between fungi and plants, as well how these effects mediated plant community composition did not been fully elucidated.
In this study, we investigated the host specificity of root-associated fungi of different plant species in a subtropical monsoon forest south China. We collected 179 entire root systems from eight different plant species. For each root individual, we detected the fungi community in the root by high throughput sequencing of ITS and culture single fungi colony on PDA media. To evaluate the host specificity of these pathogenic strains, we performed bioassays with 20 fungi and inoculated into seedlings of four plant species.
Results/Conclusions
From high-throughput sequencing data, we analyzed the community composition of root-associated fungi, and found significant differences in fungal group across the eight plant species. Moreover, based on inoculation assays, we discovered 61 culturable pathogens from roots of all plant samples, revealing fungi we found have strong pathogenicity on their own seedlings grown, and some colonies (Rhodotorula sp., Cylindrocladiella pseudohawaiiensis and Pestalotiopsis mangifolia et al) showed significant host specificity in shade-house experiment.
In conclusion, our work provided strong evidences for host specificity of root-associated fungi on plant species in subtropical forest, and substantiates suggest fungi community may promote species coexistence by producing a low density and uniform dispersion of adults of these tree species. Ongoing analyses will determine whether abiotic and biotic factors would effect this host-specific.