干热河谷木棉丛枝菌根真菌鉴定及多样性分析

采集5个不同水热条件流域的木棉根系及根际土壤样品，通过形态学及分子生物学方法鉴定AMF的种类并分析其多样性及不同流域之间的差异性。结果表明，AMF种类分布于7科7属17种，多样性指数从高到低依次为金沙江流域、元江流域、澜沧江流域、怒江流域和珠江流域，表明干旱程度越高，AMF孢子密度越大。属于横断山脉的地区具有相似的AMF物种组成，属于云贵高原的珠江流域具有特殊的AMF组成。主成分分析发现，纬度、海拔、年均降水量、年均蒸发量是影响AMF多样性的第1主成分，经度、年均温度为第2主成分。研究认为与经纬度有关的地带性气候和与海拔有关的局部地形对干热河谷的AMF多样性产生了直接的影响。

Identification and Diversity of Arbuscular Mycorrhizal Fungi (AMF) and Microorganisms of Bombax ceiba in Dry-Hot Valley

Under different hydrothermal conditions in the dry-hot river valley area in Yunnan,all the trees of Bombax ceiba grow well.Whether the wide range adaptability of B.ceiba to different habitats is related to its symbiotic AMF diversity is a scientific issue concerned in this paper.Samples of B.ceiba roots and relative rhizosphere soils were collected from five river reaches in the valley with different hydrothermal conditions.The species diversity and difference of AMF were analyzed by morphology and molecular biology methods.Seventeen AMF species belonging to 7 genera and 7 families were found.The values of diversity index of the AMF found in different river reaches were in the order (from high to low) of Jinsha River,Yuanjiang River,Lancang River,Nujiang River,and Zhujiang River,indicating that the higher the drought degree,the higher the AMF spore density.The regions belonging to the Hengduan Mountains had similar AMF species composition,while the reaches of Zhujiang River,whcih belongs to Yunnan-Guizhou Plateau,had special AMF composition.Principal component analysis showed that latitude,altitude,annual precipitation and annual evaporation were the first principal components affecting the AMF diversity in dry-hot valley,and longitude and annual temperature were the second principal components.In conclusion,the zonal climate related to longitude and latitude and the local terrain related to altitude have a direct impact on the AMF diversity in the dry-hot valley.