Diversidade genética entre e dentro de populações de Cenostigma tocantinum Ducke

Abstract

C. tocantinum (Caesalpinoideae) is an arboreal and shrubby species, native to Brazil and its wood is used in building and the trees are used in afforestation projects. This study aimed to evaluate genetic diversity among and within C. tocantinum populations used in afforestation projects by AFLP markers. Ninety plants were sampled in three populations in cities of the state of Amazonas: Manaus, Parintins and Presidente Figueiredo. The AFLP markers were efficient for the genetic differentiation of populations, revealing 186 loci, 132 (71%) being polymorphic, from four combinations of primers. The mantel test indicated that geographical distance is correlated with the genetic differentiation among populations (r: 0.5034, P = 0.001), which may have been influenced by gene flow. The clustering and Bayesian cluster analysis permitted the identification of genetic similarity between the populations of Manaus and Parintins. However, most genetic diversity occurs within populations. The inter-and intra-population variations were 36.6% and 63.4%, respectively. For an arboreal species, such as C. tocantinum, used in urban afforestation projects, the introduction of plants into news projects coming from appropriate sampling in other populations assists in the genetic conservation of the species.