PS 59-44 - Neighboring plant influences on fungal communities: Do invasive species alter AMF communities and pathogen loads in native grasses

Thursday, August 11, 2011
Exhibit Hall 3, Austin Convention Center
Daniel L. Mummey1, Ylva Lekberg2, Lauren N. Stoffel1 and Philip W. Ramsey1, (1)MPG Ranch, Missoula, MT, (2)Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, MT

Invasive plant species can alter biotic communities and ecosystem processes  in ways that are detrimental to native species. A number of studies suggest that invasive species acquire fewer pathogens and utilize symbiont communities differently than native species. A small body of work suggests that the presence of invasive plant species can alter AMF communities within roots of neighboring native plant species but knowledge of how other fungal taxa are influenced has not been investigated . In this study we hypothesized that the invasive forb Euphorbia ersula (leafy spurge) alters the fungal community in roots of neighboring Pseudoroegneria spicatum (bluebunch wheatgrass), a native grass species. Roots were collected from P. spicatum individuals inside and outside four geographically isolated E. ersula patches, and from E. ersula individuals from each patch. Root materials of each plant were examined for AMF percent root colonization using microscopy. Fungal communities were examined using massive parallel sequencing of the ribosomal internal transcribed spacer (ITS1-5.8S-ITS2).  


Our preliminary results indicate significant differences in AMF percent root colonization between E. ersula and P. spicatum, but not for P. spicatum sampled inside and outside E. ersula patches. Analysis of ITS1 and ITS2 amplicons derived from each species indicated that E. ersula hosts a greater abundance of AMF relative to non-AM fungi compared  to P. spicatum.  AMF diversity in E. ersula was surprisingly low and consisted primarily of Glomus intradices sequences or close relatives.  P. spicatum roots yielded relatively large numbers of non-AM fungi, including fungi that are pathogens or close relatives of pathogens.  These results suggest that pathogen loads are low, and symbiont abundance is high, in the invasive forb relative to the native grass.

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