PHYLOGENETIC STUDIES OF THREE GENERA - SENNA, CHAMAECRISTA AND CASSIA OF SUBTRIBE CASSIINAE

Three genera of Subtribe Cassinae – Cassia, Chamaecrista and Senna were used in the study to reveal phylogenetic relationships between them. They are puzzling genus in taxonomy, since the morphological characterization is confusing in delimiting the taxa. The need of morphological study of genus is due to its importance in ethnomedicine. Most of the species are distinguishable only after fruiting. So they are wrongly identified and used in medicines producing negative effects. The present study is an attempt to compare the morphological and molecular analysis of selected species of Senna viz. S. alata, C. absus, S. occidentalis, S. tora and Cassia fistula from Thrissur which will provide useful information about the similarities and dissimilarities between the species even before fruiting period. Morphological characterization comprised of altogether 32 traits were done to calculate the similarity coefficient between the five species using the formula by Sneath & Sokal (1973) and clustering analysis were done by constructing a dendrogram. Four genetic regions were selected for molecular analysis-ITS2, rbcL, matK and psbA-trnH and sequences were downloaded from NCBI.