Species diversity of endophytic fungi in Sarcandra glabra and its antifungal activity against the black spot pathogen of Colletotrichum dematium

Abstract

One hundred and nine endophytic fungi were isolated from different S. glabra tissues at four locations, with a total isolation rate of 60.56%, belonging to 1 phylum, 2 classes, 9 orders, 21 genera and 28 species. Colletotrichum, Diaporthe and Phomopsis were the dominant genera and they accounted for 2.93, 12.84 and 10.09% of the total strains, respectively. The isolation frequency of Colletotrichum from Du 'an county was significantly higher than that from other locations (17.43%). The isolation frequencies of Colletotrichum and Diaporthe from the stems of S. glabra were the highest, at 19.27 and 8.26%, respectively, and these were significantly higher than for other tissues. Diversity and similarity analysis showed that the diversity, richness and evenness indexes from the different regions were highest from Guangxi, followed by Du 'an county. The leaf diversity index was the highest (1.26), while the stem richness and evenness indexes were the highest (4.32 and 0.49, respectively). The highest similarity coefficient of endophytic fungi among different regions was 55.32% in Du 'an and Jingxi counties. The root and stems had the highest similarity coefficient of 97.14%, indicating that species composition and diversity of endophytic fungi in the different regions and tissues of S. glabra were affected. In addition, the metabolites obtained from the crude extracts of the two endophytic fungi had the strong inhibitory effects on 11 pathogens. Phomopsis heveicola and Neofusicoccum parvum had the strongest inhibitory effects of Botrytis cinereal and Botrytis sp., with inhibitory rates of 100%.