罗汉果内生真菌多样性研究.

Involved in the biological co-existence, endophytic fungi can confer adaptative advantages to the plant host, such as enhance growth, competitiveness, and induce stress tolerance and the producing of bioactive metabolites of the host plant, displaying an important role in biocontrol of plant diseases. There are many species of endophytic fungi in plants. The identification based on amplification and sequencing analysis of ITS gene, combined wdth traditional morphological identification methods, could fast and effectively identify endophytic fungi. In this study, the identification as wrell as the diversity of endophytic fungi isolated from Siraitia grosvenorii wrere studied. The results wrere as follows ： A total of 150 endophytic fungi 'were obtained by a tissue culture method, including 96 and 54 fungal isolates respectively isolated from pistillate plant and staminiferous plant of S. grosvenorii. Among them, 122 isolates 'were classified into nine genera based on the morphology identification and sequencing analysis of ITS gene, wrhich belong to phylum Ascomycota, including Dothideomycetes and Sordariomycetes. Dothideomycetes contained three families and three genera, and Sordariomy- cetes contains six families and six genera. The most frequent genera wrere Colletotrichum and Fusarium. There wrere different colonization rates and isolation rates between pistillate plant and staminiferous plant of S. grosvenorii, i.e., in the pistillate plant, the root possessed the highest colonization rate and isolation rate, wrhile the leaves possessed the lowest. The opposite happened in staminiferous plant. Additionally, distributions of endophytic fungi "were different in different tissues of both pistillate plant and staminiferous plant of S. grosvenorii. Combined wdth the similarities of community composition of endophytic fungi in different tissues, the results indicate that endophytic fungi have the hosts and tissues preferences. The diversity indices of endophytic fungi in different tissues ranged from 0.11 to 0.69, among 'which the root of pistillate plant had the highest diversity indices. [ABSTRACT FROM AUTHOR]