Molecular Characterization and Micropropagation Of Selected Varieties of Banana (Musa Spp.)

Abstract

Banana is one of the most important fruit crops in many tropical and subtropical countries including India). Banana is an important member of the kingdom plantae, family musaceae of the order zingiberales and belongs to genus Mus a. The banana and plaintains have a basic chromosome number of X=ll with 22 (diploid), 33 (triploid) and 44 (tetraploid) chromosomes. SSR and RAPD markers were used to characterize eight banana (Musa spp.) cultivars collected from western and central U.P. and genetic diversity were assessed. Out of 10 SSR primers 9 produced clear, reproducible and discrete bands with moderate polymorphism. The average number of alleles amplified per primer was 3.2, ranging from 2 to 4, with a total of 29 alleles identified. Phenetic analysis based on Jaccard's similarity index derived from presence or absence of the alleles and a fairly good polymorphism present. Bootstrap analysis divided the genotypes into three clusters, according to cultivars geographical locations. For RAPD analysis 20 primers used and only 8 primers gave amplification. Out of total 35 bands scored 20 were Monomorphic and 15 were polymorphic. Jaccard's coefficient of similarity ranges from 0.666- 0.903 , which again showed a moderate polymorphism among the selected banana cultivars. In both SSR and RAPD analysis, cultivar C I showed maximum dissimilarity on UPGMA cluster analysis for genetic similarity, therefore selected for micropropagation study. A micropropagation protocol for cultivar C 1 optimized using different concentration and combinations of plant growth regulators NAA and BAP. NAA (0.5 mg/1) and BAP (6.0mg/l) was optimum to get maximum shoots proliferation per explants. All plants were rooted on half MS media and acclimatized successfully. These results indicate that the micropropagation protocol developed by this study may be used for fast in-vitro multi pi ication (micropropagation) of banana.