title: Fine-scale genetic structure and gene dispersal inferences in 10 neotropical tree species.
abstract: The extent of gene dispersal is a fundamental factor of the population and evolutionary dynamics of tropical tree species, but directly monitoring seed and pollen movement is a difficult task. However, indirect estimates of historical gene dispersal can be obtained from the fine-scale spatial genetic structure of populations at drift-dispersal equilibrium. Using an approach that is based on the slope of the regression of pairwise kinship coefficients on spatial distance and estimates of the effective population density, we compare indirect gene dispersal estimates of sympatric populations of 10 tropical tree species. We re-analysed 26 data sets consisting of mapped allozyme, SSR (simple sequence repeat), RAPD (random amplified polymorphic DNA) or AFLP (amplified fragment length polymorphism) genotypes from two rainforest sites in French Guiana. Gene dispersal estimates were obtained for at least one marker in each species, although the estimation procedure failed under insufficient marker polymorphism, limited sample size, or inappropriate sampling area. Estimates generally suffered low precision and were affected by assumptions regarding the effective population density. Averaging estimates over data sets, the extent of gene dispersal ranged from 150 m to 1200 m according to species. Smaller gene dispersal estimates were obtained in species with heavy diaspores, which are presumably not well dispersed, and in populations with high local adult density. We suggest that limited seed dispersal could indirectly limit effective pollen dispersal by creating higher local tree densities, thereby increasing the positive correlation between pollen and seed dispersal distances. We discuss the potential and limitations of our indirect estimation procedure and suggest guidelines for future studies.
authors.affiliation: Université Libre de Bruxelles, Service d'Eco-Ethologie Evolutive, CP 160/12, 50 Av. F. Roosevelt, B-1050 Brussels, Belgium. ohardy@ulb.ac.be
authors.forename: Olivier J
authors.initials: OJ
authors.lastname: Hardy
authors.forename: Laurent
authors.initials: L
authors.lastname: Maggia
authors.forename: Eric
authors.initials: E
authors.lastname: Bandou
authors.forename: Peter
authors.initials: P
authors.lastname: Breyne
authors.forename: Henri
authors.initials: H
authors.lastname: Caron
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Chevallier
authors.forename: Agnès
authors.initials: A
authors.lastname: Doligez
authors.forename: Cyril
authors.initials: C
authors.lastname: Dutech
authors.forename: Antoine
authors.initials: A
authors.lastname: Kremer
authors.forename: Céline
authors.initials: C
authors.lastname: Latouche-Hallé
authors.forename: Valérie
authors.initials: V
authors.lastname: Troispoux
authors.forename: Vincent
authors.initials: V
authors.lastname: Veron
authors.forename: Bernd
authors.initials: B
authors.lastname: Degen
mesh_terms: D005616:French Guiana; D005819:Genetic Markers; D014644:Genetic Variation; D018895:Microsatellite Repeats; D008957:Models, Genetic; D021141:Nucleic Acid Amplification Techniques; D011110:Polymorphism, Genetic; D019105:Random Amplified Polymorphic DNA Technique; D014197:Trees / Q000235:genetics*; D014329:Tropical Climate
chemical_list: D005819:Genetic Markers