Estrutura genética em microescala espacial de Myrcia splendens (Myrtaceae)

Abstract

In fragmented ecosystems, very common in southern Minas Gerais, vegetation corridors are ecologically important elements for gene flow. Vegetation corridors in Lavras, MG, are narrow (from 3 to 6m), with secondary vegetation formed by trench colonization and they connect primary vegetation fragments. In both environments, it is common the occurrence of Myrcia splendens, which produces fruit with zoocoric dispersion. The objective of this work was to evaluate spatial genetic structure in fine-scale of Myrcia splendens (SW.) in environments with fragments and in their connections. Ten ISSR primers were used to access the genetic patterns in 168 trees distributed in five fragments and in 104 trees distributed in four vegetation corridors, totalizing 70 polymorphic loci. AMOVA revealed that most of the genetic diversities occurs within the the populations (96.49% in the fragments and 91.15% in the corridors). In the primary formations (F1 to F5) and in the corridors C1 and C2, the genotypes are randomly distributed. It was noted in C3 and C4 corridors, spatial genetic structure with positive and significant coancestry in the first distance class with Sp = 0.012 (P = 0.009) and 0.014 (P = 0.029), respectively.