ASSESSMENT OF GENETIC DIVERSITY IN TINOSPORA CORDIFOLIA BY INTER SIMPLE SEQUENCE REPEATS (ISSR) AND EXPRESSED SEQUENCE TAGGED- SIMPLE SEQUENCE REPEATS (EST-SSR)
Objective: In this study, assessment of genetic diversity was carried out using two kinds of molecular markers: Inter-Simple Sequence Repeats (ISSR) and Expressed Sequence Tag Simple Sequence Repeats (EST-SSR) in T. cordifolia.
Methods: A total of 20 primers/primer pairs were tested for the detection of polymorphism. For genetic diversity assessment, certain parameters such as Polymorphic Information Content (PIC), Marker Index (MI), effective multiplex ratio (EMR) and DDI (Diversity detecting Index) were used.
Results: The PIC, MI, EMR and DDI values ranges from 0.306-0.351, 0.76-1.18, 3.86-2.16 and 0.739-0.175 respectively. Cluster analysis based on Jaccard`s similarity coefficient using an Unweighted Pair Group Method with Arithmetic mean (UPGMA) classified all 24 accessions in to two major clusters respectively for both the marker system which demarcated the accessions according to different climatic zones. Similarity indices ranged from 0.68-1.0 for ISSR and 0.52-0.96 for EST-SSR.
Conclusion: Both marker systems ISSR and EST-SSR separate out the accessions from different climatic zones in to different groups. In addition, both have shown a high genetic diversity and a good consistency among different genotypes of T. cordifolia. Out of these two, EST-SSR proves more efficient as it directly correlates with the geographical distribution of the plant
