Arbuscular mycorrhizal fungi and rhizospheric soil bacteria diversity along an altitudinal gradient in South American Puna grassland

LUGO MA; FERRERO M; MENOYO E; ESTÉVEZ MC; SIÑERIZ F; ANTON A

MICROBIAL ECOLOGY

SPRINGER

Año: 2008 vol. 55 p. 705 - 713

0095-3628

Rhizospheric soil samples were taken from Puna native grasses along an altitudinal gradient. Biodiversity of arbuscular mycorrhizal fungi (AMF) and associated bacteria was analyzed considering altitude and grasses photosynthetic pathways (metabolic type C3, C4). Cultivation-dependent approaches were applied to obtain further information about the phylogeny of the dominating cultivable aerobic–heterotrophic bacteria communities present in rhizospheric soil samples. In average, the bacterial count ranged between 1.30×102 and 8.66×104 CFU g−1 of dry weight of soil. Individual bacterial colonies of aerobic heterotrophic bacteria grown on R2A medium were morphologically grouped and identified as typical soil bacteria belonging to the genera Bacillus, Pseudomonas, and Arthrobacter. Ten AMF taxa were found: Acaulospora sp., A. laevis, A. spinosa, Gigaspora sp., Gi. ramisporophora, Glomus sp., Gl. aggregatum, Gl. ambisporum, Gl. sinuosum, and Scutellospora biornata. AMF diversity decreased with altitude.