|DE LIMA, NATACIA EVANGEL - Universidad De Sao Paulo|
|MANFRIN, MAURA HELENA - Universidad De Sao Paulo|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2016
Publication Date: 9/26/2016
Citation: De Lima, N.I., Meerow, A.W., Manfrin, M. 2016. GENE FLOW AS A GENETIC HOMOGENIZATION EVENT BETWEEN POPULATIONS OF ACROCOMIA ACULEATA (JACQ.) LODD. EX MART AND A. TOTAI MART (ARECACEAE). Meeting Abstract.
Technical Abstract: Technical Abstract The taxonomy of species of the genus Acrocomia (Arecaceae) is unclear. Some authors recognize two species: the caulescent Acrocomia aculeata and the acaulescent A. hassleri (Barb. Rodr.) W. J. Hahn; while others in recognition of the high phenotypic diversity assume the presence of ecotypes, subspecies or more species. Different morphological traits are recognized between A. aculeata and A. totai Mart such as the absence of remnants of leaves on the stem of the latter. Here we aimed to evaluate if the genetic composition between populations of these species was different. Samples were collected representing its distribution in Brazil, including 157 and 55 individuals from 29 and 11 localities corresponding to A. aculeata and A. totai respectively. We used a molecular data set based on polymorphism of six microsatellites (SSR) loci and four non-coding regions, from nuclear-nuc- (PRK717-969 and WRKY16) and chloroplast-cp- (trnH-psbA and atpI-atpH). Genetic diversities of A. aculeata (hnuc;cp= 0.89; 0.72, He= 0.48) and A. totai (hnuc;cp= 0.86; 0.42, He= 0.50) were similar, which was also verified when they were analyzed as one unique species (hnuc;cp= 0.90; 0.82, He= 0.49). Significant differentiation was found among the species, however it was low for nuclear markers (Fctnuc;ssr = 0.047; 0.070) and high for matrilineal heritage (Fctcp= 0.46). The differentiation due to variation among populations within species was higher than among species (Fstnuc;cp;ssr = 0.56; 0.86; 0.24). Likewise, it was high when populations were considered as one species (Fstcp;ssr=0.81; 0.263), but no significant differentiation was found for nuclear sequence. Structure analyses suggested a k=2 for all markers, however it was not correspondent to the different species, instead showed a mixed pattern, with populations from different species sharing lineages. The species are distributed in open areas of Cerrado Savannah, apparently without restriction of gene flow, with a flexible reproductive system (both autogamous and allogamous); and pollination by wind and insects. The flowering in terms of individuals fits a “multiple-bang” model, and at the population level a “cornucopia” model. All these ecological aspects plus the success in colonizing areas, may have contributed to the homogenization by gene flow between populations, which could prevent speciation. Our molecular data suggest that A. aculeata and A. totai should be treated as different species. (Agricultural Research Service-USDA/ARS-, CAPES 006795/2015-03, CNPq 447697/2014-5)