Diversity of the Rhizosphere Soil Fungi of the Invasive Plant (Solanum rostratum Dunal) and the Allelopathic Potential of Their Secondary Metabolites

  Objective  The aim of this study was to evaluate the diversity and allelopathic effect of culturable rhizosphere soil fungi of the invasive plant Solanum rostratum so as to obtain strains with plant growth regulatory activity and evaluate their potential to be utilized as plant growth promotive agents or bioherbicides.

  Methods  Genomic DNA of the rhizosphere soil of Solanum rostratum was extracted and its 18s region was amplified and analyzed via high-throughput sequencing; meanwhile, ethyl acetate extract of the PDB fermentation broth of isolated fungi strains were tested for their biological activities using Amaranthus retroflexus and Poa pratensis as test species.

  Result  Ascomycota was found to be dominant in the fungal community of the rhizosphere soil, and the fungi community exhibited high diversity as shown by Alpha diversity analysis. Fungi strain SR02, SR05 and SR13 had strong growth inhibitory activity on the tested plants.

  Conclusion  The culturable dominant fungi were evident in the rhizosphere soil of S. rostratum, and the Fusarium oxysporum and Alternaria alternata were the most abundant. Fungi strains were found to possess significant plant promoting or inhibitory activities, and their possible physiological and ecological significance as well as their potential to be explored as plant growth regulators or herbicides is worthy to be further investigated.