Molecular identification, diversity and functional characterization of fungal communities isolated from Stipa purpurea

Abstract

Our study provided the characteristics of the fungal composition and diversity associated with rhizosphere soil, root and leaf of Stipa purpurea, and evaluated the capacities of fungal strains on promoting plant growth. A total of 293 isolates were gained from 1048 tissue segments and rhizosphere soil of S. purpurea collected from Gansu, Qinghai and Tibet by traditional methods. It was evaluated for polyketide synthases (PKS), non-ribosomal peptide synthetases (NRPS), plant growth-promoting (PGP) and antagonistic activities. The fungal isolates spread over 14 order and 42 different genera. Aspergillus was the most dominant genus of S. purpurea gained from Gansu and Qinghai, and was the second most dominant at Tibet, Fusarium was the most dominant genus in Tibet. The Simpson and Shannon diversity indices were the highest in roots of Tibet. The PCR were successful in screening 8 fungal PKS and 85 fungal NRPS gene fragments. Among 86 isolates (containing PKS/NRPS) tested, 37 strains were confirmed with indole-3 acetic acid (IAA) producing activity of which 21 produced the IAA more than 10 mg L − 1, 27 isolates were showed as strains with phosphate-solubilizing activity while 12 isolates turned out to have siderophore producing activity, and 12 exhibiting 1-aminocyclopropane-1-carboxylate deaminase (ACCD) positive. The dual culture experiment showed that some fungi had strong antagonistic activity against plant pathogens. This study explored the possible application of PGP activities with potential benefits to the host, which the fungal could promoting high biomass production and increasing the resistance or durability of S.purpurea to an hostile environment.