ibclogo XVI International Botanical Congess


Abstract Number: 2886
Session = 19.8.3


ESTIMATING POLLEN FLOW AND EFFECTIVE POPULATION SIZES OF FRAGMENTED ENTEROLOBIUM CYCLOCARPUM POPULATIONS IN COSTA RICA


V. Apsit, J Hamrick, J. Nason, Univ. of Georgia


Pollen immigration and equivalent relative gamete production may retard loss of heterozygosity and offset negative effects of genetic drift on the future genetic composition of small, extinction-prone populations. Through allozyme analyses, we examined levels of genetic diversity, mating system, pollen immigration (m), and effective population sizes (Ne) in six small (N=3-35), spatially isolated populations of E. cyclocarpum in NW Costa Rica. Moderate levels of genetic diversity and high outcrossing rate estimates suggest inbreeding is not a problem. Pollen immigration is substantial and the fairly equivalent gamete production produced only moderate reduction in Ne relative to census population sizes. Direct estimates of m and Ne allowed us to predict moderate effects of genetic drift on the probability of fixation in future populations.


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