Spatial genetic structure ofManilkara maxima(Sapotaceae), a tree species from the Brazilian Atlantic forest

Abstract

Abstract:Habitat fragmentation may lead to spatial genetic structuring of plant populations, but the magnitude of this effect differs among species. In this study, the effects of fragmentation on spatial genetic structure ofManilkara maxima, an ecologically important tree species endemic to the Atlantic forest of southern Bahia, Brazil, were examined. To address this issue, 222 individuals were sampled across two large-forest sites (200 and 400 ha) and one site comprising eight small fragments (5, 10 and 25 ha) roughly 35 y old. Five microsatellite loci were used. In general,M. maximaexhibited limited genetic structuring within and across the sites examined. At the landscape scale, genetic structure was not shaped by isolation by distance. Within individual sites, weak to moderate genetic structure was observed for both adults and saplings, which represented pre- and post-fragmentation, respectively. Sapling genetic structure did not clearly vary among the study sites, suggesting fragmentation has not affected spatial genetic structure. High levels of migration were observed, which would help maintain genetic connectivity. Taken together, these results suggestM. maxima, a long-lived tree that naturally occurs in low densities, may have limited spatial genetic structuring both within and across forest patches.

Distinctions in Fine-Scale Spatial Genetic Structure Between Growth Stages of Picea jezoensis Carr.

“…Thus, our two working hypotheses were confirmed by this study. First, the decline in FSGS over the life history was previously reported for various tree species ( Hamrick et al, 1993 ; Epperson and Alvarez-Buylla, 1997 ; Lian et al, 2008 ; Schroeder et al, 2014 ; Ganzhorn et al, 2015 ), and has been attributed to the demographic thinning of individuals. Second, the previously mentioned inbreeding depression might also have weakened the FSGS in our study.…”

Genetic diversity and structure of the treeManilkara zapotain a naturally fragmented tropical forest

“…maxima , genetic diversity (H O and H E ) in large forests and recently shaped forest fragments (35 y old) also fell within the same range (0.50–0.74; Ganzhorn et al . 2015). Manilkara zapota (and closely related species) therefore seems to maintain high genetic diversity in a variety of habitats, including continuous forest, young and old forest fragments and managed populations (Thompson et al .…”

“…maxima ) that did have more replicates (eight fragments and two large forests) (Ganzhorn et al . 2015).…”

“…Even though only three microsatellite loci were used, we consider our results to be reliable because the genetic diversity reported is very close to that reported in recent studies, even with the same species in Mesoamerica, as well as with other congeners (Ganzhorn et al . 2015, Thompson et al . 2015).…”

Structure and genetic diversity in wild and cultivated populations of Zapote mamey (Pouteria sapota, Sapotaceae) from southeastern Mexico: its putative domestication center

“…In recent years, several studies within the Sapotaceae family have reported high levels of genetic diversity in wild species such as: Argania spinosa L. Skeels (H E = 0.67, Yatrib et al 2017); Manilkara maxima (H E = 0.67, Ganzhorn et al 2015); Pouteria reticulata (Engl.) Eyma (H E = 0.71, Schroeder et al 2014); Manilkara zapota (H E = 0.95, González-Hernández et al 2012); and Manilkara huberi (Ducke) Standl (H E = 0.86, Azevedo et al 2007; H E = 0.78, Rennó 2007).…”