关键词: 小黄花茶, 内生真菌, 分离鉴定, 多样性, 抑菌活性

Abstract: In order to explore the species and population distribution of endophytic fungi in Camellia luteoflora, as well as their inhibitory effects on plant pathogenic fungi, this study used tissue separation method to isolate and purify endophytic fungi in C. luteoflora. These fungi were identified based on morphology and molecular biology, and their diversity was evaluated through statistical analysis. The strains with antibacterial activity were screened out by the plate confrontation method. The results were as follows:(1)A total of 261 strains of endophytic fungi were isolated from 324 C. luteoflora tissue samples, belonging to 1 phylum, 5 classes, 9 orders, and 22 genera. The dominant genera were Colletotrichum, Diaporthe and Pestalotiopsis with isolation frequencies of 21.84%, 16.86% and 10.34%, respectively.(2)The distribution of endophytic fungi in C. luteoflora varied in different seasons. The highest number of strains was isolated in winter(72 strains, accounting for 27.59%, belonging to 16 genera), 62 strains were isolated in spring(belonging to 13 genera), 59 strains were isolated in summer(belonging to 15 genera), and 68 strains were isolated in autumn(belonging to 13 genera). The Shannon-Wiener index(H'), Simpson index(D), Pielou's evenness index(E), and Margalef's richness index(M)were the highest in winter. The similarity of endophytic fungal species between spring and winter was higher, and the similarity between summer and autumn was higher.(3)The distribution of endophytic fungi also varied in different parts of C. luteoflora. The stems had the most abundant endophytic fungi, with 102 strains accounting for 39.08%(belonging to 15 genera), 61 strains were isolated from the roots(belonging to 10 genera), and 98 strains were isolated from the leaves(belonging to 15 genera). The H', D, E, and M were highest in the stems, and the endophytic fungal species in the leaves were most similar to those in the stems.(4)The plate confrontation results showed that among the 35 tested endophytic fungi, 26 endophytic fungi had inhibitory effects on at least one plant pathogenic fungi, accounting for 74.29%, among which CJ-Ⅱ-2, XY-V-3, QY-Ⅱ-4, QJ-Ⅲ-2 and DJ-I-2 had inhibitory effects on eight plant pathogen fungi to varying degrees. XY-V-3 had the best inhibitory effect on eight plant pathogenic fungi, and the inhibitory rate was higher than 50%. XY-V-3 and QJ-Ⅲ-2 have higher inhibitory rate than 50% on two strains of pathogenic fungi in C. luteoflora, which had the potential to control disease of C. luteoflora. To sum up, the diversity of endophytic fungi in C. luteoflora is rich, and some of the strains have higher effect of inhibiting plant pathogenic fungi, which lay a foundation for the research and development of biological control products and the disease control of C. luteoflora.

Key words: Camellia luteoflora, endophytic fungi, separation and identification, diversity, antibacterial activity