中国特有的三种榆科植物枝条内生真菌菌群多样性

摘要

为了解我国特有的3种古老的野生榆科植物内生真菌菌群多样性及探讨同一生境条件下内生真菌菌群在不同植物之间的组成特征,以安徽琅琊山国家森林公园内的野生青檀、琅琊榆和醉翁榆的当年生健康枝条为研究对象,采用组织分离法和形态分类学方法对其内生真菌进行了分离和鉴定.结果表明,从3种榆科植物的1 778个组织块中,分离内生真菌1 938株,隶属于10目16科22属,未产孢的一类暂归为无孢菌群,占10.2％.3种榆科植物均是以子囊菌类所占比例最高(80.72％-89.71％),目级水平以肉座菌目Hypocreales的相对多度最高,科级水平以间座菌科Diaporthaceae的相对多度最高,属级水平以拟茎点霉属Phomopsis的相对多度最高.琅琊榆枝条中分离的内生真菌菌群最多(14属),醉翁榆菌群最少(10属).内生真菌菌群组成在3种榆科植物之间存在宿主特异性.Shannon指数(H')从高到低的顺序为:青檀＞琅琊榆＞醉翁榆,Margalef指数(R)从高到低的顺序为:琅琊榆＞青檀＞醉翁榆,均匀度指数(E)从高到低的顺序为:青檀＞醉翁榆＞琅琊榆.琅琊榆和醉翁榆之间的内生真菌菌群组成相似度最高,相似性系数达0.62,青檀和琅琊榆的相似性系数最低(Cs=0.44).费舍尔检验(Fisher's exact test)表明,3种榆科植物在内生真菌菌群组成上无明显差异(P=0.26-0.50＞0.05).%Community composition and diversity of endophytic fungi from the branches of three ancient and endemic wild plants of Ulmaceae in China were investigated,and characteristics of fungal community composition in the different plants with same habitat condition were compared.Healthy branches of current year of Pteroceltis tatarinowii,Ulmus chenmoui,and Ulmus gaussenii were collected from Langyashan forest park,Anhui Province,the natural distribution areas of the plants.Endophytic fungi were isolated from branch tissue,and fungal strains were classified on the basis of morphology.From 1 778 tissue samples of the plants,1 938 isolates of endophytic fungi belonging to 22 genera,16 families,and 10 orders were identified.Unsporogenous strains were classified as Mycelia sterilia (10.2％).Ascomycetes were the most dominant in Pteroceltis tatarinowii (89.71％),Ulmus chenmoui (88.96％),and Ulmus gaussenii (80.72％),and next came the species of Hypocreales,Diaporthaceae,and Phomopsis.The most genera were isolated from Ulmus chenmoui (14 genera),and the less from Ulmus gaussenii (10 genera).The Shannon index (H') ranked in sequence of Pteroceltis tatarinowii＞Ulmus chenmoui＞Ulmus gaussenii,while Margalef index (R) Ulmus chenmoui＞Pteroceltis tatarinowii＞Ulmus gaussenii and Evenness index (E) Pteroceltis tatarinowii＞Ulmus gaussenii＞Ulmus chenmoui.The community in Ulmus chenmoui and that in Ulmus gaussenii were most similar (Cs=0.62),while community in Pteroceltis tatarinowii and that in Ulmus chenmoui were the least similar (Cs=0.44).Fisher's exact test showed no significant difference (P=0.26-0.50＞0,05) between the composition of endophytes from Pteroceltis tatarinowii,Ulmus chenmoui,and Ulmus gaussenii.