贵州赤水桫椤自然保护区桫椤内生真菌多样性研究

桫椤Alsophila spinulosa是白垩纪时期遗留的古老孑遗蕨类植物,具有较高的药用价值和观赏价值。本研究采用形态特征和ITS序列分析方法,从250个组织块中共分离获得84个菌株,隶属于2门3纲10目18科25属。子囊菌门Ascomycota为优势菌门,其相对丰度高达92.86%,而担子菌门Basidiomycota仅为2.38%;粪壳菌纲Sordariomycetes和座囊菌纲Dothideomycetes为优势纲,其相对丰度分别为78.57%和13.10%;小丛壳目Glomerellales和炭角菌目Xylariales为优势目,其相对丰度分别为33.33%和25.00%;小丛壳科Glomerellaceae和炭角菌科Xylariaceae为优势科,其相对丰度分别为32.14%和19.05%;刺盘孢属 Colletotrichum和炭角菌属Xylaria为优势属,其相对丰度分别为32.14%和14.29%。这些菌株存在一定的组织差异,属水平上,叶轴中共获得15属,特有属9属;羽状复叶中共获得16属,特有属10属,两组织间共有属为6属,其中刺盘孢属Colletotrichum和炭角菌属Xylaria均为两组织的优势属,但其相对丰度存在一定差异。从不同组织多样性来看,桫椤叶轴的Shannon、Simpson多样性指数和Pielou均匀度均高于桫椤叶。

Diversity of endophytic fungi from Alsophila spinulosa in Chishui Alsophila National Nature Reserve,Guizhou Province,Southwest China

Alsophila spinulosa is a mesozoic ancient relic fern species with high medicinal and ornamental value. A total of 84 isolates of culturable endophytic fungi was isolated from A. spinulosa, and 2 phyla, 3 classes, 10 orders, 18 families and 25 genera were identified by morphology and ITS rDNA sequence analysis. Ascomycota was the dominant phylum, with relative abundance of 92.86%, while Basidiomycota was only 2.38%. Sordariomycetes and Dothideomycetes were the dominant classes, with relative abundance of 78.57% and 13.10%, respectively. Glomerellales and Xylariales were dominant orders, with relative abundance of 33.33% and 25.00%, respectively. Glomerellaceae and Xylariaceae were dominant families, with relative abundance of 32.14% and 19.05%, respectively. Colletotrichum and Xylaria were dominant genera, with relative abundance of 32.14% and 14.29%, respectively. At the genus level, 15 and 16 genera were found in the rachis and pinna, respectively, of which 9 and 10 genera were specific in the rachis and pinna, respectively, including 6 genera in common. Colletotrichum and Xylaria were dominant in rachis and pinna. Shannon, Simpson and Pielou index of endophytic fungi in rachis were higher than those in pinna.