Knowledge on genetic diversity provides basic information about population dynamics and functioning aiming both to conservation and sustainable use of species. It is assumed that early successional populations could genetically be more differentiated than those in late sucessional stages. To test this hypothesis, the genetic variability of Eugenia uniflora L. populations at different successional stages was investigated. Two areas at different successional stages were selected; one at early successional stage, showing several pioneer trees, and another at late successional stage. The area in study (27º54'S and 52º13'W) is covered by a remnant forest in transition from Mixed Rain Forest to Seasonal Semideciduous Forest. RAPD (Random Amplified Polymorphic DNA) and multivariate analysis were used to evaluate the expected genetic diversity and percentage of polymorphism as well as genetic similarity within and between areas and the genetic diversity by the Simpson diversity index. Results indicated 79% of polymorphic loci for the area at late successional stage and 70% for the area at early successional stage. Pairwise genetic similarity varied from 0.55 to 0.86 in the area at early successional stage and from 0.45 to 0.78 in the area at late successional stage. No differences were found for diversity between the areas (P = 0.89). A non-metric multidimensional scaling showed lower genetic distances among individuals from the area at early successional stage. Similarly, the analysis of similarities - ANOSIM -indicated a split between individuals of both areas.
disturbed areas; forest fragmentation; RAPD
