Diversity Studies in Ecotypes of Banana ( Musa Spp.) Using Molecular Markers and D 2 Analysis

The present study was aimed at analyzing the genetic diversity of promising banana ecotypes grown in Kerala. Twenty eight ecotypes of banana were collected from different parts of Kerala. DNA isolated from these was used for RAPD analysis. Six most-promising primers viz., OPA-01, OPA-03, OPA-13, OPB-04, OPB-10 and OPB-12 were used. These yielded 46 scorable bands with an average of 7.66 bands per primer. RAPD data were analyzed statistically and a dendrogram was constructed. Twenty three characters were observed in the twenty eight banana ecotypes and were statistically analyzed as per the method proposed by Mahalanobis (D²). From RAPD dendrogram, it was found that the banana clones clustered into fourteen groups at a distance of 0.200. At a distance of 0.250, 8 out of 12 Nendran (AAB group) ecotypes formed a single cluster at the same distance. Among Palayankodan (AAB group) ecotypes PKNNR, Pisang Ceylon, Motta Poovan, Chandra Bale and Palode Palayankodan grouped together and formed a single cluster. Attu Nendran, Monthan, Robusta, Koonoor Ethan, Ilavazha and Vellapalayankodan formed individual clusters and had maximum genetic divergence. Among diploid clones, Ilavazha (BB group) had maximum genetic divergence. Among triploid clones, Attu Nendran, Robusta, Koonoor Ethan and Vellapalayankodan showed maximum genetic divergence. Among Nendran (AAB group) ecotypes, Attu Nendran and Koonoor Ethan revealed maximum genetic divergence. Among Palayankodan (AAB group) ecotypes, Vellapalayankodan recorded the highest genetic divergence. In D² analysis too, a similar trend was observed.