Molecular diversity of arbuscular mycorrhizal fungi associated with two alpine plant species in the Tibetan Plateau

Abstract

Alpine ecosystem in the Tibetan Plateau has a special ecological environment, which may harbor a high richness of arbuscular mycorrhizal fungi (AMF) communities. To explore the molecular diversity of AMF community associated with plants in alpine grasslands, root and rhizosphere soil of two dominant plant species, Kobresia sp. and Leontopodium pusillum in Qinghai province, were studied by molecular biotechnology (clone library and sequencing) at five sites for each plant species. A total of 30 operational taxonomic units (OTUs) were identified, including seven families of Glomeromycota. Glomeraceae and Glo1 and Glo2 were most abundant at family and OUT level in roots respectively, while both Glomeraceae and Diversisporaceae were frequently present and Glo1 and Div1 were the most dominant OTUs in the soil. The AMF community was different in the roots and soil. Nineteen OTUs were identified in the roots of Kobresia sp., and 21 OTUs were identified in the rhizosphere soil. As to L. pusillum, fourteen OTUs were identified in roots and 17 OTUs in the soil. Specifically, three OTUs were only found in L. pusillum, and eight OTUs were only found in Kobresia sp. The root biomass and soil C/N ratio were the main factors affecting the AMF community in roots, whereas in soil, the important factors were root carbon content and shoot nitrogen content. These results showed a high diversity of AMF associated with the typical alpine plants, and distinct AMF community exist in roots and soil. Our results confirmed the importance of plant and soil factors in driving AMF assemblages in the fragile ecosystem of Tibetan Plateau.