A phylogenetic analysis of the Cucurbitaceae: evidences from matk nucleotide sequences

MaturaseK gene (matK) of chloroplast is highly conserved in plant systematics which is involvedin Group-II intron splicing. The size of the gene is approximately 1500 base pairs in length, located with inthe intron of trnK. In the present study, matK gene from Cucurbitaceae was taken for the analysis ofvariants, parsimony site, patterns, transition/ transversion rate and phylogeny. The family Cucurbitaceaecomprises over 120 genera and 825 species with medicinal values. The matK gene sequences have beenwithdrawn from GenBank and used for the analysis. The multiple sequence alignments were performed byGenebee-ClustalW. The phylogenetic analyses were carried out by MEGA (Molecular Evolutionary GeneticsAnalysis) software package based on Unweighted Pair Group Method with Arithmetic Mean (UPGMA) andMaximum Parsimony (MP) methods. The results indicated that the Trichosanthes, Austrobryonia,Momordica, Neoalsomitra, Gomphogyne, Sicyos genera showed polyphyletic condition. The overallinvariants between the 88 taxa are 28.5%, average composition of nucleotides among taxa are found to beapproximately, A-0.30, T-0.37, G-0.15, C-0.17 and the ratio of transition and transversion is 0.824.Phylogenetic tree was designed to identify the ideal regions that could be used for defining the inter andintra-generic relationships. From this study, it could be concluded that, the chloroplast matK genesequences can unambiguously resolve the relationships, as well as provided a good indication of majorsupra-generic groupings among the selected members of the family Cucurbitaceae.