Study of Genetic and Phenotypic Variability among Somaclones Induced by BAP and TDZ in Micropropagated Shoot Tips of Banana (Musa spp.) Using RAPD Markers

The effects of different concentrations of Benzylaminopurine (BAP) and Thidiazuron (TDZ) on somaclonalvariation based on genetic and phenotypic variability among micropropagated shoot tips of banana cultivars; ‘Berangan Intan’, ‘Berangan’ and ‘Rastali’ were studied. With the highest concentrations of both BAP and TDZup to 44.4μM and 7.5 μM, respectively, most shoots were curled and other morphological changes such ashyperhydricity and undifferentiated shoots were observed. Detectable genetic changes to reveal stable variationsamong 27 micropropagated variants produced by BAP and TDZ were confirmed using Random AmplifiedPolymorphic DNA (RAPD) markers. The percentages of polymorphism among somaclones of banana cultivars; ‘Berangan Intan’, ‘Berangan’ and ‘Rastali’ regenerated by TDZ were 24.4, 27.3 and 29.5, respectively whichwas higher than BAP treatment with the percentages of 16.7, 24.2 and 24.7, respectively. The number ofscorable bands among the RAPD profiles obtained with 19 primers tested in this study varied from 6 for opa11and opk03 to 18 by opc01 in somaclones derived from BAP and 4 for opk03 to 14 with opa04, opb18 and opc04in the case of TDZ. Cluster analysis of the somaclones regenerated with each of BAP and TDZ resulted in theformation of two major groups, one belonging to Berangan Intan and Berangan (AAA) and the other to Rastali (AAB). From each dendrogram caused by BAP and TDZ, it could be concluded that regenerated somaclones byhigher concentrations of both BAP and TDZ accumulated much genetic variation compared to the control andlower concentrations of each of BAP and TDZ.