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为了解黄瓜植株内生真菌的区系组成及其变化,从而为进一步研究黄瓜内生真菌的生态和功能奠定基础,对采自北京延庆的不同品种和不同生育期的40株黄瓜进行了内生真菌的分离培养。经形态学鉴定和18S rDNA序列分析,分离到的1,024株内生真菌属于18属,其中Exserohilum和Neocosmospora尚未见内生真菌的报道。Alternaria、Aspergillus、Chaetomium、Cladosporium和Fusarium在各生育期和各器官普遍存在。其中,Alternaria在叶中的定殖率达47.0%,远高于在其他器官中的定殖率;Fusarium在根中的定殖率达32.5%,远高于在其他器官中的定殖率。多数真菌类群表现出不同程度的器官偏好性,有些真菌类群则只出现在特定器官中。叶和根的内生真菌类群数量和总定殖率均高于茎和果实。随着黄瓜的生长,各器官内生真菌的类群数在增加,部分真菌的定殖率也呈上升趋势,但Neocosmospora和Chaetomium在各器官中的定殖率则随植株生长呈下降趋势。
In order to understand the floristic composition and changes of endophytic fungi in cucumber plants, and to lay the foundation for the further study on the ecology and function of endophytic fungi in cucumber plants, 40 cucumber cultivars from different varieties and different growth stages were collected from Yanqing, Beijing Isolation and culture of fungi. The morphological identification and 18S rDNA sequence analysis showed that 1,024 endophytic fungi isolated belong to 18 genera, of which Exserohilum and Neocosmospora have not been reported yet. Alternaria, Aspergillus, Chaetomium, Cladosporium and Fusarium are prevalent in every growth period and every organ. Among them, Alternaria’s colonization rate in leaves was 47.0%, much higher than that in other organs. Fusarium colonization rate in roots was 32.5%, much higher than that in other organs. Most fungal groups show varying degrees of organ preference, while some fungal groups appear only in specific organs. Leaf and root endophytic fungi groups and the total colonization rate was higher than the stems and fruits. With the growth of cucumber, the number of endophytic fungi in each organ increased and the colonization rate of some fungi increased. However, the colonization rate of Neocosmospora and Chaetomium decreased with plant growth.