Potential impact of landscape genetic diversity in macauba populations in a fragmented landscape

Abstract

Acrocomia aculeata (macauba) has economic and ecological importance, exhibits genetic complexity shaped by factors related to its reproduction, pollination, and dispersal mechanisms. Research indicates high genetic diversity for the species. However, threats such as habitat fragmentation in the Cerrado ecoregion may lead to a decline in this diversity. Thus, this study aimed to quantify the genetic diversity of macauba in a fragmented area by investigating the genetic clustering of populations and evaluating the impact of the original population composition on genetic diversity and differentiation among populations. To achieve this, DNA samples were collected from macauba progenies, followed by extraction and genotyping using an Axion customized array. Subsequently, the selected genotypes were grouped according to the study area, categorized as natural, anthropized, and transitional. Molecular variance analysis, heterozygosity estimates, and Principal Coordinates Analysis were conducted to understand the genetic structure of the population. The results indicate that the genetic diversity of A. aculeata is complex and not solely limited to habitat fragmentation. Genetic markers revealed variations not directly linked to geographical location or habitat categorization. This suggests the existence of gene flow between populations, possibly facilitated by animal movement, including cattle, and human activities. Moreover, the study emphasizes that future research should expand geographic sampling to capture a more comprehensive representation of the species populations across different regions of its natural distribution.