Filogeografia de caryocar villosum (aubl.) pers. (caryocaraceae) no baixo Rio Negro (AM) e subsídios para a sua conservação

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

Caryocar villosum (Caryocaraceae) is an Amazonian "terra-firme"emergent tree threatened because of Amazonia fragmentation and deforestation. This study examined the phylogeography of C. villosum to test the hypothesis that the Rio Negro is a geographical barrier to maternal gene flow and to generate useful information for conservation strategies. Expanded leaves of 38 individuals, 14 from the right margin and 24 from the left margin of the Negro River, were sampled for DNA extraction. The phylogeography of C. villosum was based on the sequencing of a chloroplast non-coding region between the genes trnT and trnF. The amplified fragments were sequenced and aligned using the software ClustalX. Thirty three different haplotypes were found. Analysis of molecular variance showed that genetic differentiation among individuals of the same margin was higher than among individuals from right and left margins. The median-joining network analysis did not show distinct clusters for individuals from different margin, and haplotypes from different margins presented common maternal origin. Additionally, we found many haplotypes occurring in both margins, but no haplotypes were shared among individuals from different margins. These results suggest that different maternal lineages may have colonized both margins before the Negro River attained its current basin size and that no recent events of maternal gene flow have been occuring between the margins. Nevertheless, the results could also be the outcome of homoplasy, probably due to independent mutations, or other factors such as human population movements, and consequent seed dispersal. Conservation planning for C. villosum may consider the occurence of different haplotypes in the same population for in-situ conservation in Reserves and for core collection for ex-situ conservation.

ASSUNTO(S)

ciências biológicas caryocaraceae cloroplasto conservação árvores - filogenia genética de populações filoseografia proteção ambiental

ACESSO AO ARTIGO

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