Abstract

In order to solve the insufficient supplement of important medicinal and agricultural plantTripeterygium silfordii, the endophytic fungi which may produce active compounds were studied in this work. 86 endophytic fungi strains from plant T. wilfordii were isolated and their larvicidal activities were studied in this paper. Morphological observation preliminarily indicated that these fungi belong to 10 genera, in which Fusarium, Pesalotiopsis,Alternaria and Thizoctonia are the dominant flora, accounting for 24.4, 14.0, 11.6 and 10.5% of the total isolated strains, respectively. The metabolites from 86 strains were further extracted to determine their ability to kill mosquito larvae. The results indicate that the ethyl acetate extracts of 16 strains’ mycelium exhibit Larvicidal activity, accounting for 18.6% of the isolated strains; and the ethyl acetate extracts of fermentation broth for nine strains (10.5%) showed the larvicidal activity. The active strains were focused in generaAspergillus, Penicillium, Phoma and Pesalotiopsis. In addition, the ethyl acetate extracts of one stain’s mycelium contained 8.03 μg wilforgine per gram dry mycelium weight in HPLC analyze, which was further grouped into Pestalotiopsis malicola based on the morphological and phylogenetic analysis of its  internal transcribed spacer  (ITS) sequencing.

Key words: Tripterygiun wilfordii Hook, endophytic fungus, insecticidal activity, internal transcribed spacer (ITS) sequence, alkaloids