Filogenia e biogeografia do complexo Croton pallidulus(Euphorbiaceae), inferidas por sequências de DNA e marcadores AFLP / Phylogeny and biogeography of complex Croton pallidulus (Euphorbiaceae), inferred by DNA sequences and AFLP markers

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

15/12/2011

RESUMO

The project addressed the detection of genetic polymorphisms in a Complex formed by some species of widespread occurrence in southeast of Brazil, whose limits are not yet well established, by presenting great morphological polymorphism that raises doubts as to whether it is a single or various species. The following species were studied: C. ceanothifolius, C. dichrous, C. erythroxyloides, C. aff. erythroxyloides, C. myrianthus, C. pallidulus var. pallidulus, C. pallidulus var. glabrus and C. splendidus. The purpose of this study was to evaluate the consistency of the species studied by means of phylogenetic analysis based on sequences of ITS and two chloroplast DNA regions (trnL-F and rps16), and by AFLP markers (Amplified Fragment Length Polymorphism). Was used as outgroup C. urucurana. As additional objectives, we tried to study the phylogeography of the species complex, through analysis of disjunct populations distributed from the Southeast to the South. Phylogenetic inferences were made from DNA sequences, performed by the criteria of maximum parsimony and posterior probabilities (Bayesian analysis). The results were a great union of most species of the Complex in a polytomy; the populations of C. dichrous and C. aff. erythroxyloides emerged separately in a clade, apart from two populations of C. pallidulus var. glabrus with C. myrianthus, besides the three populations of C. pallidulus var. pallidulus and other species of Complex emerging in another clade. For the AFLP technique, we obtained polymorphic fragments used as characters in the genetic affinity relationships through the neighbor-joining analysis (performed using the PAUP). It was observed that the two varieties of C. pallidulus emerge in different clades, while the two populations of C. pallidulus var. glabrus emerge in the same clade, C. pallidulus var. pallidulus appeared as a paraphyletic taxon, as it appears grouped with different species, a result that confirms the distinct nature of these two varieties. C. erythroxyloides and C. aff. erythroxyloides shown by the two methods of molecular analysis, to be distinct species. C. splendidus, C. ceanothifolius and C. myrianthus are not well resolved, blending, often with C. pallidulus var. pallidulus. Finally, there was congruence between the topologies obtained with the analysis based on combined sequencing data with that obtained by AFLP. The study of biogeography indicated that the distribution area of the ancestral group is probably wide, situated between Minas Gerais and Santa Catarina, since the distribution of species of the complex occurs preferentially in those states

ASSUNTO(S)

aflp aflp complex croton pallidulus complexo croton pallidulus filogenia molecular molecular phylogeny

ACESSO AO ARTIGO

Documentos Relacionados