Estudos moleculares em Hypochaeris catharinensis Cabrera (Asteraceae) utilizando marcadores AFLP

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

25/02/2010

RESUMO

Hypochaeris catharinensis (Asteraceae) is endemic to south Brazil. In this work we used AFLP molecular marks (Amplified Fragment Length polymorphism) aiming to determine the genetic structure of H. catharinensis and to define its phylogenetic position within the South American group of the genus Hypochaeris. To define the phylogenetic position of H. catharinensis, eleven AFLP selective primer combinations were used in eigth diferent South American Hypochaeris plus H. catharinensis and H. angustifolia, used as outgroup. The results showed three main phylogenetic groups, as defined in previous studies. Hypochaeris catharinensis formed a tight association (90% booststrap) with H. lutea, giving origem to a new phylogenetic group, named Lutea group. This group is also supported by the similarities observed on the karyotypes of H. catharinensis and H. lutea. Together these data provide valuable information that may help to elucidate the processes of adaptative radiation of the genus Hypochaeris into the South American continent. Six AFLP primes combinations, applied in 11 populations of H. catharinensis coleted from the Santa Catarina and Rio Grande do Sul states, rendered 183 frangents of which 165 (90,16%) were polymorphic. AMOVA, applied to the AFLP data revealed that the genetic variability was higher within (83,64%) than among (16,36%) populations. Principal Coordinate Analysis showed that most of the 11 populations studied have individuals that are mixed in other populations, revealing the absence of a clear pattern in the genetic structure. The recent divergence of the South American Hypochaeris, together with the morphological and ecological characterists that favour the seed dispersion of H. catharinensis, may have contributed to the low level of divergence observed among populations of this species.

ASSUNTO(S)

genética de populações hypochaeris catharinensis plantas - genética molecular polimorfismo (genética) populations genetics plant molecular genetics plantas - filogenia

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