Genetic analyses of micropropagated and regenerated plantlets of banana as assessed by RAPD and ISSR markers

• Published in: In vitro cellular & developmental biology. Plant 2007-05, Vol.43 (3), p.267-274
• Main Authors: Venkatachalam, L., Sreedhar, R. V., Bhagyalakshmi, N.
• Format: Article
• Language: English
• Subjects: Banana; bananas; Binding sites; buds; Competition; Cultivars; Cytokinins; Deoxyribonucleic acid; DNA; Endangered; explants; gels; Genetic diversity; Genetic stability; genetic variation; genotype; Genotype & phenotype; in vitro regeneration; Industrial research; ISSR; kinetin; leaves; MICROPROPAGATION; microsatellite repeats; Musa; Plant cells; Plant genetics; Plantlets; Plants; Polymerase chain reaction; random amplified polymorphic DNA technique; RAPD; Regeneration; risk; Scholarships & fellowships; shoots; Somaclonal variation; tissue culture
• ISSN: 1054-5476; 1475-2689
• DOI: 10.1007/s11627-007-9028-7

A cultivar of dessert banana, namely, Nanjanagudu Rasabale (NR), classified under group “silk” (of genotype AAB), is seriously under the threat of extinction due to its susceptibility to bacterial wilt and bunchy-top virus disease. A regeneration protocol using tissue culture method was developed (Venkatachalam et al. 2006), where a large number of plantlets were regenerated from leaf base explants. Simultaneously, a micropropagation protocol was also developed where high levels of up to 53.28 μM of benzylamino purine (BAP) and 55.80 μM of kinetin (Kn) were used. The progressive increase of cytokinins levels resulted in concomitant increase in shoot number, with a maximum of 80 shoot buds per segment in BAP (31.08 μM). The plantlets were analyzed for their genetic stability using randomly amplified polymorphic DNA (RAPD) and inter simple sequence repeats (ISSR) markers. A total of 50 RAPD and 12 ISSR primers resulted in 625 distinct and reproducible bands showing homogeneous RAPD and ISSR patterns. Band intensity histogram of each gel confirmed their monomorphic nature with no genetic variation among the plantlets analyzed. The present study has established for the first time that the regeneration and rapid micropropagation protocol developed through the present study will be of great use in conserving the endangered cultivar – NR – without risk of genetic instability.