不同海拔的三种杓兰属植物与菌根真菌群落组成相关性

本研究采集了四川黄龙沟沿海拔梯度3 170-3 400m上4个不同杓兰居群中3种杓兰植物根,利用克隆文库方法获得菌根真菌ITS序列,研究同一栖息地（黄龙沟）不同海拔梯度和不同杓兰对菌根真菌多样性和群落结构的影响。共得到18个可操作分类单元（OTU）,其中14个OTU隶属胶膜菌科Tulasnellaceae,为优势类群（99.6%）;2个OTU隶属腊壳菌科Sebacinaceae,2个OTU隶属亡革菌科Thelephoraceae。随着海拔升高,西藏杓兰菌根真菌多样性减少,而黄花杓兰和无苞杓兰没有明显变化;海拔对3种杓兰菌根真菌群落结构均无显著影响。3种杓兰之间菌根真菌群落结构差异显著且指示物种互不相同,说明在同一栖息地,杓兰对菌根真菌的偏好性显著影响其菌根真菌群落结构。这些研究结果利于了解环境变化对杓兰属植物菌根真菌区系组成的影响,为进一步探索菌根真菌与杓兰属植物的互作机制奠定基础。

Correlation between vertical distribution of three Cypripedium species and composition of orchid mycorrhizal fungal community

The roots of three Cypripedium species (C. tibeticum, C. flavum and C. bardolphianum) growing at different altitude (3 170-3 340m) in Huanglong valley, Sichuan Province of China, were sampled. Culture-independent method was used to obtain orchid mycorrhizal fungal (OrMF) ITS sequences from the roots. The correlation between vertical distribution of three Cyprepedium species and mycorrhizal fungal community composition was investigated. A total of 18 different operational taxonomic units (OTU) were detected. Among them, 14 OTUs were assigned to family Tulasnellaceae composing dominant taxa (99.6%), two OUTs were affiliated in the family Sebacinaceae, and the others in Thelephoraceae. With the incease of altitude, the OrMF diversity of C. tibeticum decreased, while that of the other two Cypripedium species was unchanged. There were no significant differences in OrMF community composition between the three Cypripedium species at different altitude. Different Cypripedium species growing in the same habitat showed significant differences in OrMF community composition, and the dominant mycorrhizal OTUs were also different.