In vitro tissue culture techniques and colchicine-induced polyploidy in Banana (Musa, AA group) ‘Kluai Khai’

Abstract

Background and Objective: In vitro tissue culture techniques for both shoot and root induction and the colchicine-induced approach on the banana (Musa, AA group) ‘Kluai Khai’ cultivar have been very limited. The purpose of this research was to determine the optimal conditions for plantlet regeneration and polyploidy induction in Kluai Khai. Materials and Methods: Shoot tips of banana were cultured on Murashige and Skoog (MS) solidified medium amended with 6-benzylaminopurine (BAP) at different concentrations for shoot induction and the obtained shoots were transferred to MS medium containing Naphthalene Acetic Acid (NAA) at different concentrations for root induction. For polyploidy induction, banana shoots were transferred to liquid MS medium supplemented with various concentrations of colchicine (0, 0.05, 0.10, 0.15 and 0.20%) for 1, 2, 3, 4 and 5 days. Results: MS medium supplemented with 2.5 mg L-1 BAP was most effective in inducing shoot multiplication, with maximum shoots per explant and height of shoot. MS medium amended with 0.5 mg L-1 NAA was most appropriate for rooting (100%) with an average of 9.30 roots per shoot and a length of 5.48 cm. Moreover, the treatment with 0.15% colchicine for 3 days appeared to be the most effective combination for generating tetraploids, with the highest viability of explants. Moreover, in terms of leaf anatomy, the tetraploid plants had larger stomata than the diploid of Kluai Khai. Conclusion: MS medium supplemented with 2.5 mg L-1 BAP and 0.5 mg L-1 NAA were optimal conditions for the shoot and root induction and 0.15% colchicine for 3 days was most effective for tetraploids generation of Kluai Khai banana.