Cladistic analyses of a few members of Cucurbitaceae using rbcL nucleotide and amino acid sequences

The rbcL gene and protein sequences have been used in addressing systematic questions amongthe few selected members of the family Cucurbitaceae has been investigated. In order to elucidate thesystematic positions, a set of chloroplast-rbcL nucleotide sequences (from 42 taxa of 7 genera) andaminoacid sequences (from 52 taxa of 10 genera) were withdrawn from GenBank and GenPept databases,respectively. The evolutionary distance was inferred from these sequences by employing Bootstrap methodof UPGMA (Unweighted Pair Group Method with Arithmetic Mean) and MP (Maximum Parsimony) usingMEGA (Molecular Evolutionary Genetic Analysis) software. From the separate analysis produced almostsimilar although not identical results, no strongly supported incongruent results. The members of the genusAustrobryonia showed strictly monophyletic, Trichosanthes, Luffa, Momordica and Coccinia are found to beparaphyletic. But the members of the genus Cucumis are distributed throughout these hiraeoid clades,confirming the polyphyly of this large genus observed in both the family trees. From the results, it is alsoclear that, the chloroplast-rbcL gene and aminoacid sequences resolved the relationships, as well asprovided a good indication of major supra-generic groupings among the selected members of the familyCucurbitaceae. These results provide the necessary frame work and explicit phylogenetic hypotheses fromwhich further reversionary and other systematic studies can proceed.