Molecular Diversity of Arbuscular Mycorrhizal Fungi Associated with Two Dominant Xerophytes in a Valley-Type Savanna, Southwest China

The diversity of arbuscular mycorrhizal fungi (AMF) colonizing the roots and rhizosphere soils of Heteropogon contortus and Dodonaea viscose growing in a valley-type savanna, southwest China, were analyzed by the large subunit ribosomal RNA genes (LSU). A total of 547 AMF sequences were screened for establishment of four clone libraries. Phylogenetic analysis revealed that the sequences clustered in at least 8 discrete sequence groups, all belonging to the genus Glomus. Among the Glomus spp., Glo 1 (GlGr A) and Glo 7 (GlGr B) were the most common in all root and soil samples of the two xerophytes, accounting for 42% and 33% of all screened clones, respectively. The ∫-LIBSHUFF analysis revealed that the composition of AMF communities associated with the two xerophytic hosts varied greatly both in roots and their rhizosphere soils.