Variabilidade genética entre e dentro de populações naturais de Zizyphus joazeiro Mart. e Cassia grandis L.f., por meio de marcadores moleculares

Abstract

The genetic diversity within and among natural populations is critical to developing strategies for conservation in situ and ex situ, due to forest fragmentation alters ecological processes that are essential to maintaining this diversity. This study was conducted to evaluate the genetic variability within and between populations of Zizyphus joazeiro Mart. and Cassia grandis L.f. by molecular markers, to define strategies for collect of the seed to produce seedlings for the rehabilitation of degraded areas. The study was realized in different municipalities in the Baixo São Francisco sergipano. Populations of Z. joazeiro were sampled in Santana do São Francisco, Canhoba e Canindé do São Francisco, while populations of C. grandis were sampled in Santana do São Franciso, Canhoba e Nossa Senhora de Lourdes. To evaluate the genetic structure of populations were used isozymes and RAPD-DNA marker. From the observed results can be inferred that due to forest fragmentation, mainly caused by human occupation in the Baixo São Francisco, the populations are structured. However, the species showed high genetic diversity within populations, inbreeding and lack of rare alleles and unique. These results should be linked, in addition to forest fragmentation, pollination characteristics of the studied species (insects), for as short distances, gene flow is not large, which can lead to the genetic structure of populations. Thus, strategies for conservation of variability, such as the collection of genetic material in all populations studied, should be adopted.