Population genetic structure of Neotropical mangrove species on the Colombian Pacific Coast:: Pelliciera rhizophorae (Pellicieraceae)

Pelliciera rhizopborae is a Neotropical mangrove species whose distribution is mostly restricted to the Pacific Coast, between the Gulf of Nicoya (Costa Rica) and the Esmeraldas River (Ecuador). In the Caribbean, patches of Pelliciera have been found in Nicaragua, Panama, and Colombia. The genetic variation and the population structure of P rhizophorae were evaluated in six zones of the Colombian Pacific, using AFLP molecular markers. Of the 225 amplified fragments produced, 155 (69%) were polymorphic in 57 individuals of P rhizopborae collected in the localities of Virudo, Charambira, La Plata Island, Tumaco, Milagros, and Chontal. Genetic diversity within populations varied significantly, with the lowest levels of within-population variation (H-ep = 0.081 and 0.090, respectively) in La Plata Island and Tumaco; and the highest level of variation (Hep = 0.187) in Chontal. In the Colombian Pacific, P rhizophorae was significantly structured, with 26.5 percent of the variation found among populations, which was an evidence of substructure within populations. Genetic differentiation was not related to the geographic distance between zones. This suggests that the population dynamics of P rhizophorae could be associated with historic processes influenced by ecological and environmental factors such as the movement of pollen by birds, the displacement of propagules by marine currents, and the spatial distribution of favorable habitats.