Genetic diversity in forest populations from conservation units in the Atlantic Rainforest in northeast Brazil

Abstract

Fragmentation leads to changes in the size and dynamics of forest populations. Studies of genetic diversity support strategies for preserving the genetic resources, and the data to date for the Atlantic Forest in northeast Brazil is scarce. Thus, the objective of this study was to evaluate the genetic diversity of Protium heptaphyllum (Burseraceae) tree species in three populations. We sampled 64 individuals in this study, for which seven primers used generated 90 loci, with 93% being polymorphic. The average number of alleles was 1.59, the effective number of alleles was 1.34, Nei’s genetic diversity was 0.20, and the Shannon index was 0.30. AMOVA indicated higher genetic variation among individuals within populations than among populations. Bayesian analysis revealed the existence of two distinct genetic groups, in which the MAC (Macaiba) population was the most differentiated. Genetic bottleneck tests indicated that all populations presented significant reductions in the population size. In situ conservation strategies must be adequately maintained considering the current isolation of studied populations, the genetic bottleneck, and the low average genetic diversity detected. Also, further recovery of degraded areas in the vicinity and ex situ conservation are recommended.