Impact of cefotaxime on in vitro shoot elongation and regeneration in banana (Musa acuminata)

Abstract: This is the first report of antibacterial and growth promoting effectiveness of cefotaxime in banana tissue culture. Young suckers (3-13 cm diameter) of commercially important banana varieties viz., 'Grand Naine' and 'Robusta' were regenerated into shoots on MS-medium supplemented with 6-benzylaminopurine (BA, 5 mgL^-1) and multiplied on Banana Multiplication Medium (BMM) for 7 cycles of 3 weeks each. Shoots were separated and cultured on BMM supplemented with IBA (1.0 mgL^-1) and cefotaxime at various concentrations viz., 0, 100, 200, 300, 400, 500, 600 and 700 mgL¹. Maximum shoot multiplication and elongation with respect to number of shoots, shoot length and plantlet fresh weight in both the genotypes was obtained with cefotaxime used at the rate of 400 and 500 mgL^-1 in the medium. Among the different varieties, on the basis of mean of 50 shoot cultures, number of shoots per culture and shoot length was highest in cv. Robusta i.e. 7.20 (41.6% increase over control) and 8.50 cm (30.5% increase over control), respectively. Whereas, plantlet fresh weight was highest in cv. Grand Naine (494.8 mg, 38.9% increase over control) after 3 weeks of culturing with cefotaxime used at the rate of 500 mgL^-1. Results revealed significant differences among varieties and media for different shoot multiplication and elongation parameters. Therefore, use of cefotaxime during tissue culture and genetic transformation of banana can improve frequency of shoot multiplication and transformation, respectively.