西藏中部野生宿主植物 AM 真菌生态分布的研究

目的]为阐明高寒生态区域下野生宿主植物与AM真菌的共生关系。方法]以西藏中部草地生态系统为研究对象。结果]在主要建群种植物根围土壤中共分离到4属21种AM真菌，AM真菌平均孢子密度为2．74＋／g，种的丰度、多样性指数、物种均匀度分别为2．10种／土样、2．68、0．88。结论]西藏高原AM真菌各属分布极不平衡，摩西球囊霉为优势种；近明球囊霉为最常见种。莎草科、藜科等以前被认为不能与AM真菌形成菌根的植物其根系在研究中均能被AM真菌侵染。根区孢子密度、种的丰度均为最高，而豆科植物侵染率及其丛枝丰度最高。12种寄主植物中，苔草根区AM真菌孢子密度、种的丰度均为最高，猪毛菜最低。

Study on Ecological Distribution of AM Fungi of Wild Host Plants in the Middle of Area of Tibet

The research aimed to study the symbiotic relation of wild host plants and AM fungi in high and cold ecoregion, Method] The research object was grass ecological system in the middle of Tibet. Result] 4 families, 12 kinds of plant roots from the soil in Tibet were infected with arbuscular mycorrhizal fungi that belonged to 21 species, four genus. The AMF spore average density was 2.74 per g soil, the species richness was 2.10 per soil sample, the species diversity index was 2.68, and the species evenness was 0.88. Conclusion] The distribu- tion of AM fungi was unbalanced. G. mosseae was of prominent species, and G, clarodium was of the most common species. AM fungi also showed a relatively high infection rate on the roots of plant which couldn＇t be infected before such as Cyperaceae and Chenopodiaceae. The highest spore density and the best species richness of the 4 families belonged to Cyperaceae while Leguminosae had the highest infection rate and the best arbuscule richness. For different host plants, the highest spore density and the best species richness belonged to Carex tristachya while Salsola nepalen- s/s was the lowest.