三尖杉内生真菌的遗传多样性研究

Genetic Diversity of Endophytes Isolated from Cephalotaxus fortunei

本研究以三尖杉的根、茎、叶中分离的91株内生真菌为材料,根据其菌落颜色、质地、生长速率和分生孢子外观等形态学特征,确定了其中74株产孢内生真菌为5个属。采用特异性PCR对91株菌株的ITS片段进行扩增,获得单一的分子长为600 bp的条带,以4种限制性内切酶对扩增的ITS片段进行RFLP分析,并对部分ITS碱基序列进行测定,表明三尖杉内生真菌的属和种丰富,其中的优势属为刺盘孢属、曲霉属及小丛壳属,表现为热带真菌类型;小丛壳属是首次从三尖杉科植物中分离。本研究结果提示三尖杉内生真菌有丰富的遗传多样性。

To study the microecosystem and genetic diversity of endophytic fungi, 91 endophytes were isolated from the roots, stems, or leaves of Cephalotaxus fortune. Based on the morphological features of colony, as well as growth rate on potato dextrose agar （PDA） medium, 74 producing -spore endophytic fungus were classified to 5 genera. The internal transcribed spacer （ITS） fragments of rRNA gene of 91 endophtes were amplified using specific primers. A single product with 600 bp of ITS was obtained for the genomic DNA of each fungus. The polymorphisms of ITS fragment were examined by restriction fragment length polymorphism （RFLP） method using four restriction enzymes （Hinf I, Hha I, Msp I, and Pst I）. Nucleotide sequences of ITS were analyzed. The results showed that both of genera and species were abundant, and the dominant genera were Colletotrichum, Aspergillus, Glomerella which belonged to the tropical type. Glomerella was first isolated from plant of Cephalotaxus. It suggested that Cephalotaxus endophyte possessed highly genetic diversity.