TAMANHO EFETIVO E FLUXO GÊNICO EM POPULAÇÕES DE Acrocomia aculeata (Jacq.) Lodd. ex Mart. USANDO TEORIA DA COALESCÊNCIA

Abstract

Acrocomia aculeata is a tropical palm tree native to Central and South America, which has significant economic, social, and environmental potential. It has several applications and is used mainly as a source of raw material for biofuels, as well as in the culinary, pharmaceutical, and cosmetics industries. However, land encroachment due to the expansion of agribusiness, together with urban growth and other factors have resulted in the fragmentation and destruction of its habitat, leading to the loss of genes and genotypes in local A. aculeata populations. These deleterious genetic processes restrict genetic variability, affecting productivity, and the capacity of A. aculeata populations to respond to climate change and other biotic and abiotic stresses. As such, these processes can compromise the continuation of not only the species, but also its dependent flora and fauna. In this context, the objective of this study was to estimate the gene flow and effective population size using an approach based on coalescence theory. Four subpopulations located in the municipalities of Teodoro Sampaio (TSI and TSII), Rosana (RA), and Amparo (AP), São Paulo State, Brazil, were evaluated with nine microsatellite loci. In order to evaluate the effective size and gene flow, the Bayesian inference method was used, based on the coalescence theory implemented in the MIGRATE-N software. The effective population size (Ne) was obtained considering a mutation rate of 5x10-5. Gene flow (Nm) for pairs of populations ranged from 0.28 to 1.17, with higher levels of migration between the three geographically proximal locations (TSI, TSII, and RA). The estimates of effective population size (Ne) were 444, 835, 838, and 874 for AP, TSII, RA, and TSI, respectively. The results obtained add to our understanding of A. aculeata population genetics and show that some traditional methods may be unsatisfactory in making inferences about gene flow and historical evolutionary processes.