title: Arbuscular mycorrhizal fungi associated with sedges on the Tibetan plateau.
abstract: The arbuscular mycorrhizal (AM) status of nine dominant sedge species and the diversity of AM fungi in Tibetan grassland were surveyed in the autumn of 2003 and 2004. Most of the sedge species and ecotypes examined were mycorrhizal, but Carex moorcroftii and Kobresia pusilla were of doubtful AM status, and Kobresia humilis was facultatively mycorrhizal. This is the first report of the mycorrhizal status of eight of the nine sedge species examined. Intraradical vesicles and aseptate hyphae were the structures most frequently observed. Appressoria, coils, and arbuscules were found in the roots of a few sedge species. A strong negative correlation was found between soil organic matter content and the extent of mycorrhizal colonization. Using trap cultures, 26 species of AM fungi belonging to six genera, Glomus, Acaulospora, Paraglomus, Archaeospora, Pacispora, and Scutellospora, were isolated from the soil samples collected. The frequency of occurrence of different taxa of AM fungi varied greatly. Glomus and Acaulospora were the dominant genera, and Acaulospora scrobiculata was the most frequent and abundant species. The species richness of AM fungi was 2.73 in the study area. Species richness and diversity index differed among the sedge species but were not correlated with soil factors such as pH, available P, or organic matter content.
authors.affiliation: Department of Plant Nutrition, China Agricultural University, 2 Yuanmingyuan Road, Beijing, 94, China.
authors.forename: J P
authors.initials: JP
authors.lastname: Gai
authors.affiliation: College of Agricultural and Animal Husbandry, University of Tibet, Linzhi, 860000, China.
authors.forename: X B
authors.initials: XB
authors.lastname: Cai
authors.affiliation: Department of Plant Nutrition, China Agricultural University, 2 Yuanmingyuan Road, Beijing, 94, China.
authors.forename: G
authors.initials: G
authors.lastname: Feng
authors.affiliation: Department of Plant Nutrition, China Agricultural University, 2 Yuanmingyuan Road, Beijing, 94, China.|Agricultural and Environmental Science Department, Queen's University Belfast, Newforge Lane, Belfast, BT9 5PX, UK.
authors.forename: P
authors.initials: P
authors.lastname: Christie
authors.affiliation: Department of Plant Nutrition, China Agricultural University, 2 Yuanmingyuan Road, Beijing, 94, China. lixl@cau.edu.cn.
authors.forename: X L
authors.initials: XL
authors.lastname: Li
mesh_terms: D015169:Colony Count, Microbial; D029785:Cyperaceae / Q000145:classification / Q000382:microbiology*; D017753:Ecosystem; D038821:Mycorrhizae / Q000145:classification / Q000302:isolation & purification*; D018517:Plant Roots / Q000382:microbiology; D012987:Soil / Q000032:analysis; D012988:Soil Microbiology; D013045:Species Specificity; D018609:Tibet
chemical_list: D012987:Soil