The 2008 Joint Meeting of the Society for Range Management and the America Forage and Grassland Council. |
Tuesday, January 29, 2008
16
Beyond the Surface: Diversity of Arbuscular Mycorhizal Fungi (AMF) in Prairie Grasses
Michael P. Schellenberg1, Juan Carlos Perez2, Chantal Hamel1, and Jim Germida3. (1) AAFC - Semiarid Prairie Agricultural Research Centre, Box 1030, 1 Airport Road, Swift Current, SK S9H 3X2, Canada, (2) Universidad Nacional de Colombia, AA 3840, Medellin, Colombia, (3) Soil Science, University of Saskatchewan, 51 Campus Drive, Sasktoon, SK S7N 5A8, Canada
Prairie grasses are commonly associated with diverse communities of AMF, which have been demonstrated in many ecosystems to increase plant productivity and tolerance to disturbance. Assessments of AMF diversity, due to logistical problems, are usually restricted to the first 10 or 15 cm in the soil. As a result little is known about the development of symbioses beyond the first few centimetres within the soil. Many prairie plants are known to have deep roots as an adaptation to extreme environmental variations at the soil surface. In this research, samples of roots were taken from 0-15 or 30-45 cm depth during spring and summer of 2006 in pure stands of crested wheat grass (Agropyron cristatum (L.) Gaertn.), western wheat grass (Pascopyrum smithii (Rydb.) A. Löve), green needle grass (Stipa viridula Trin.) and switch grass (Panicum virgatum L.). To determine AMF diversity, we used molecular methods based on PCR amplification of ribosomal genes. DNA was extracted from pooled root samples from both seasons and clone libraries were created for each plant and depth after the PCR amplification of portions of the long sub unit ribosomal DNA (LSU rDNA) of AMF. Our preliminary results suggest the presence of different AMF communities associated with each plant species, with shifts according to root depth, and differing abundances of some AMF ribotypes in the deeper roots. Rarefaction and phylogenetic analyses are being computed in clone libraries to compare AMF diversity in roots from each plant species at different depths