Genetic diversity and gene flow in a Caribbean tre

Authors: F Muller M Voccia A Bâ J M Bouvet

Publish Date: 2008/04/23

Volume: 135, Issue: 2, Pages: 185-198

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Abstract

We analysed the molecular diversity of Pterocarpus officinalis a tree species distributed in Caribbean islands South and Central America to quantify the genetic variation within island to assess the pattern of differentiation and infer levels of gene flow with the overall goal of defining a strategy of conservation Two hundred two individuals of 9 populations were analysed using three chloroplast and six nuclear microsatellite markers The observed heterozygosity varied markedly among the populations for nuclear H Onuc = 020–050 and chloroplast microsatellites H cp = 022–068 The continental population from French Guyana showed a higher value of H Onuc than island populations and the differences were significant in some cases The fixation index F IS ranged from −0043 to 0368 a significant heterozygote deficit was detected in 7 populations The heterozygosity excess method suggested that two populations in Guadeloupe have undergone a recent bottleneck Global and pairwise F ST were high for both nuclear F STnuc = 029 and chloroplast microsatellites F STcp = 058 The neighbourjoining tree based on both markers presented a differentiation pattern that can be explained by the seed dispersal by flotation and marine stream The comparison of Bayesian approach and the method based on allelic frequency demonstrate a very limited number of migrants between populationsWe would like to thank the French Ministry MEDD Ministère de L’Ecologie et du Développement Durable for financial support in implementing the Pterocarpus officinalis project This work was supported financially by the Guadeloupe Archipelago Region and the Social European Fund We are very grateful to colleagues at CIRAD C Leroux G Bena and at the University of AntillesGuyane for assistance in collecting samples and to A Vaillant and M Poitel at CIRAD for their technical assistance in the laboratory We are grateful to the two anonymous reviewers for their helpful comments and suggestions which improve significantly the manuscript

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