| Abstrakt: |
The germination and growth of orchid seeds depend on symbiotic fungi. Holcoglossum rupestre is an endemic, narrowed distributed and critical endangered species of Orchidaceae. Aiming to better ex situ conserve H. rupestre, the plants were collected from Shangrila, Chuxiong, Kunming Panlong and Kunming Chenggong in Yunnan. The endophytic fungi in its roots were isolated and identified based on ITS rDNA sequences, and their effect on seed germination was studied. The results showed that 68 culturable fungal endophytes were isolated and identified from roots of H. rupestre from 4 localities of Yunnan province, which belonged to 18 genera of 3 classes, i.e., Sordriomycetes, Agaricomycetes and Dothideomycetes. Among all strains, Fusarium, Diaportha, Tulasnella and Ceratobasidium were the dominant fungal endophytes with 27.94%, 10.29%, 8.82% and 8.82% of relative abundance. Some orchids mycorrhizal fungi as well as Tulasnella and Ceratobasidium were firstly found in H. rupestre roots. And Tulasnella strains P2 and P47 could significantly promote symbiotic germination of Dendrobium denneanum seeds by advancing germination process and improving germination consistency. [ABSTRACT FROM AUTHOR] |
