Smallwood, P.D.*; Terzaghi, W.B.; Steele, M.A.; Carlson, J.E.; Mank, J.E: Further investigations into the interactions between small vertebrates and oaks: An interdisciplinary approach

At last year’s meeting, we reported that several species of small vertebrates consistently cache viable acorns of the red oak group much more frequently than those of the white oak group. We hypothesized that this behavior affects the structure of forests. Seedlings from red oak species should be widely dispersed from their parent trees, while those from white oaks should be clumped near the parent tree. We have now begun a long term project, utilizing molecular genetic techniques (DNA fingerprinting) to test this hypothesis directly. Here, we present an interim report on this project. We have mapped study sites in two locations, with some species in common between the sites. We have sampled over 500 adult and seedling oak trees at each site. For one site, we have isolated usable DNA from most individuals. We are now using these DNA samples to test primer pairs shown to amplify polymorphic simple tandem repeats (STRs) in other oak species, and to optimize PCR conditions for each primer set. We have identified 9 primer pairs which reliably amplify STRs with multiple alleles (determined by sizing on agarose and acrylamide gels) in Quercus alba, Q. velutina and Q. rubra. The variation at these 9 sites should allow us to assemble unique profiles for each individual. We are now matching the DNA profiles of seedlings and adult trees to identify parent-offspring pairs. This allows us to directly test our hypothesis, by measuring dispersal distances between adult trees and their offspring. As far as we know, this represents the first use of molecular genetic techniques to test specific seed dispersal hypotheses. NSF-DBI #997 8807