PARENT SESSION
Poster Session 23: Soil Ecology
Wednesday, August 10, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Molecular analysis of arbuscular mycorrhizal fungi associated with two Southeastern tree species.

Hersh, Michelle¹, Vilgalys, Rytas¹, Clark, James¹, ¹ Duke University, Durham, NC, United States

ABSTRACT- Arbuscular mycorrhizal fungi (AMF) may contribute to biodiversity of forests through species-specific effects on nutrient dynamics. To determine potential differences in the AMF community between plant host species in different forest types, we used molecular-based approaches to characterize AMF associated with two common co-occurring Southeastern tree species, Acer rubrum and Liriodendron tulipifera. Seedlings of both species were sampled in August 2004 at two ecologically distinct mixed hardwood stands, one in the North Carolina Piedmont, the other in the Southern Appalachians. Total genomic DNA was extracted from root tips of individual seedlings of both species at both sites, from which AMF DNA was selectively amplified, cloned, and sequenced. Phylogenetic analyses of 198 cloned sequences revealed fifteen AMF phylotypes across the sample, with an average of approximately 2.5 AMF phylotypes per tree seedling. The number of AMF phylotypes per seedling was similar between the two host tree species. Of the fifteen phylotypes, one was specific to A. rubrum, two were specific to L. tulipifera, ten were common to both, and two were represented by only one sequence. Two phylotypes were specific to the Piedmont site, two were specific to the Southern Appalachians, and nine were found in both sites. Nearly all sequences (195 of 198) belonged to the genus Glomus. The relatively low levels of host and site specificity suggest that a similar AMF community is shared by both tree species across different environments.

Key words: arbuscular mycorrhizae, mutualism, phylogenetics