Gene flow among populations of Croton floribundus Spreng. (Euphorbiaceae)in a primary tropical forest of São Paulo State

Abstract

Gene flow promotes genetic continuity by transferring genetic variation among populations. The process can be estimated indirectly using molecular markers. Comparisons among patterns of differentiation in nuclear and chloroplast markers can be used to estimate the ratio of pollen and seed flow. The Croton floribundus tree species is considered to be pioneer, autochoric and pollinated by flies and wind. Evaluating the gene flow among populations in a well conserved (primary) forest may highlight the factors that determine genetic diversity and structure and may help to understand the effects of patch dynamic on the population genetics for this species. Furthermore, the information is essential to design conservation strategies for Croton floribundus as well as to improve the knowledge of population genetics of tropical trees. Thus, the aim of this study is to evaluate the amplification of universal chloroplast microsatellites in Croton floribundus; to evaluate the genetic diversity and structure using chloroplast microsatellites markers; and to estimate the gene flow and the relative importance of pollen and seed migration among populations of Croton floribundus in a primary forest.