Abstract

Q. Xuan, F. K. Bao, H. M. Pan and A. H. Liu*

Eighteen fungal endophytes strains parasitizing the famous Chinese medicinal plant Paris polyphylla Smith var. yunnanensis (Franch.) Hand. Mazz were isolated from surface-sterilized plant tissues, such as rhizome, root, stem, leaf and flower. The effect of endophytes on the growth of human pathogenic microbes was evaluated in vitro, using disc diffusion assay. According to the characteristics of cultures and DNA sequences, the WRF7 and WRF7’ belonged to the species Penicillium chrysogenum. The extract of WRF7’ inhibited a broad range of human -pathogenic bacteria, but that of WRF7 almost had no similar effect. And the metabolites of WRF7’ could not stop the growth of test fungus Candida albicans. The study indicates that P. chrysogenum becomes fungal endophyte of Paris polyphylla Smith var. yunnanensis and its isolate WRF7’ makes metabolites that are inhibitory to all test bacteria in vitro. Therefore, the host plant suppressing pathogens owing to its endophytes and inhibitory mechanisms of endophytes to test bacteria and fungi are different