Gene pool sharing and genetic bottleneck effects in subpopulations of Eschweilera ovata (Cambess.) Mart. ex Miers (Lecythidaceae) in the Atlantic Forest of southern Bahia, Brazil

Abstract

Forest loss and fragmentation are the main threats to the maintenance of the Atlantic Forest, an important global biodiversity hotspot. Because of the current critical level of deforestation, ecological corridors are needed to facilitate species dispersion and gene flow among fragments. This study was conducted to investigate the genetic variability and gene pool sharing of Eschweilera ovata in five forest remnants in southern Bahia, Brazil using nuclear simple sequence repeat (nSSR) and plastid simple sequence repeat (cpSSR) microsatellite markers. cpSSR marker analysis revealed the domains of four haplotypes, showing that 80% of the individuals had only four maternal origins, reflecting a founder effect and/or genetic bottleneck. The results of cpSSR and nSSR analyses indicated moderate genetic diversity, particularly in conservation units with full protection, which showed the best parameters of all areas evaluated. Another indication of the susceptibility of these populations to forest loss and fragmentation was the strong genetic bottleneck observed. In contrast, genetic structure analyses (FST and discriminant analysis of principal components) revealed gene pool sharing between the subpopulations, which may reflect the historical gene flow that occurred before forest fragmentation.

Microsatellites are important for forest genetic resources conservation in Brazilian biomes

“…The genetic variability and gene pool sharing analysis of Eschweilera ovata revealed that there was moderate genetic diversity, particularly in conservation units with full protection, and that there was gene pool sharing between the subpopulations, which might reflect the historical gene flow that occurred before forest fragmentation (Santos et al 2019).…”

Genetic structure among the endangered Brazilian Euterpe Edulis Mart (Arecaceae) morphotypes

“…However, the Two Phase Model (TPM) and Stepwise Mutation Model (SMM) had divergent results, not detecting genetic bottleneck in any of the evaluated populations. This result was expected to some extent because, although microsatellite markers may adhere to different mutational models (AIM, TPM, or SMM), genetic bottlenecks have been reported mainly for the AIM model (Piry et al , 1999;Santos et al , 2019). The genetic bottleneck or excess of H E occurs when the population has experienced a recent reduction in effective population size, causing a reduction in the number of alleles faster than in H E (Cornuet and Luikart, 1996;Piry et al , 1999).…”