Estudo in sílico da evolução molecular da subfamília mimosoideae (Fabaceae) por meio de marcadores 18S e rbcL.

Abstract

Partial sequences o f the region o f ribosomal DNA (rDNA) 18S (total 7) and the rbcL gene (total 19) o f different species o f the Mimosoideae subfamily were obtained from GenBank. The goal o f this work was to help in the phylogenetic inference inside this subfamily. Multiple alignments o f all sequences were produced with the ClustalX program. For construction o f phylogenetic trees the MEGA package (Molecular Evolutionary Genetics Analysis) was used. The methods o f Neighbor-Joining (NJ) with 500 replications and Maximum Parsimony (MP) with 100 replications were performed. The phylogenetic tree constructed by NJ and MP methods using 18S gene showed a better resolution phylogenetic grouping species within their respective tribes, according to the classification o f the NCBI Taxonomy tool. However, at the levei o f tribe for the topologies given by NJ and MP methods with marker rbcL, unresolved clades were observed. The tribes Mimoseae and Acacieae were polyphyletic. The genus A lb izia was paraphyletic in all topologies constructed by MP and NJ methods. In this case, both topologies based on 18S and rbcL sequences do not supported the monophyletic hypostesis. In conclusion, the evolutionary history o f the Mimosoideae tribes hypothesized with rbcL gene sequences do not agree with the topologies available in the NCBI Taxonomy.