Abstract

MORPHOLOGICAL AND MOLECULAR POLYMORPHISM AMONG THE MEDICINAL HERB CASSIA OCCIDENTALIS L. ACCESSIONS FROM THIRUVANANTHAPURAM, KERALA

Aswathy JM, Meenu Krishnan VG, Greeshma GM, Greeshma Murukan and Murugan K*

Abstract

Cassia occidentalis L. is a pantropical, traditional herbal weed that invades as impenetrable thickets in open land with variable morphoforms. The taxonomic complexity of this species is caused in part by the phenotypic plasticity of the species and leads to natural intra-specific hybridization. An initial attempt was made to differentiate the accessions collected from ten localities of Thiruvananthapuram, Kerala in terms of morphology and molecular techniques. Leaf length, width and plant height showed variability. The genetic diversity of ten accessions of C. occidentalis collected from different localities were analyzed using twelve RAPD primers. 111 bands were scored corresponding to an average of 9.25 bands/ primer with 79 bands showing polymorphism (71.17%). 9 out of 12 primers gave more than 60% polymorphism. Jaccard similarity coefficient ranged from 0.54 to 0.73. A dendrogram constructed based on the UPGMA clustering method revealed two major clades. Clade 1 comprises of 8 accessions which was further differentiated into two sub-clusters while Clade 2 includes two accessions. This study showed significant genetic polymorphism among C. occidentalis accessions.

Keywords: Cassia occidentalis, Molecular analysis, SDS-PAGE, Dendrogram, Morphological.