MSA - Ecology/Pathology
Davoodian, Naveed , Rajakaruna, Nishanta .
Arbuscular mycorrhizal colonization of St. Johnís Wort (Hypericum perforatum) on adjacent serpentine and granite outcrops.
Extensive work has been conducted on elucidating the influence of ultramafic geologies on associated biota. In North America, the majority of this effort has taken place in the western region of the continent. A small but growing body of work, however, is developing for eastern North America. Serpentine soils are derived from ultramafic rocks. They are characterized by low levels of macronutrients, elevated levels of heavy metals, and a calcium to magnesium ratio of less than one. Arbuscular mycorrhizal (AM) fungi form mutualistic associations with members of most plant families and are key components of the rhizosphere. In this study, we compared the extent of AM colonization between specimens of St. Johnís Wort (Hypericum perforatum; Hypericaceae) collected from adjacent serpentine and granite outcrops on the Deer Isle complex, Maine to examine if there was differential colonization based on substrate. Colonization was assessed for the plantís main phenologic states including emergence, flowering, and senescence. Root samples were collected from the edaphically distinct top and bottom of the serpentine outcrop and throughout the granitic outcrop, and overall percent colonization at each phenologic stage was assessed. Colonization was much greater on granite than on serpentine across all phenologic states, with one exception during flowering, where colonization of plants at the top of the serpentine outcrop was found to be similar to colonization on the granite outcrop. These results are discussed in relation to the effects of edaphic factors on AM fungi and their plant associates.
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1 - College of the Atlantic, 105 Eden Street, Bar Harbor, ME, 04609, USA
2 - San Josť State University, Department of Biological Sciences, One Washington Square, San Josť, CA, 95192, USA
Presentation Type: Poster:Posters for Topics
Location: Event Tent/Cliff Lodge
Date: Tuesday, July 28th, 2009
Time: 5:30 PM