Effect of immersion systems, lighting, and TIS designs on biomass increase in micropropagating banana (Musa spp. cv. 'Grande naine' AAA)

Abstract

Development of in vitro techniques has enabled rapid clonal propagation, regeneration, and multiplication of genetically manipulated superior clones, production of secondary metabolites, and ex situ conservation of valuable germplasm. This has been possible not only due to the refinements of culture methodologies and applications of cutting-edge areas of molecular biology but also due to the judicious inclusion of engineering principles and methods to improve and refine the system. In the present study, we used engineering principles and methods to transform basic in vitro techniques into commercially viable technologies. We investigated two types of temporary immersion systems (TIS), two types of lighting, and two different gas exchange systems during in vitro banana (Musa spp. cv. 'Grande naine') shoot cultures. After 7 wks, all banana shoots cultured in standard TIS (5-L glass vessels, type 1) showed superior vegetative growth for the evaluated parameters. We also found that illumination provided by light emission diodes (LEDs) was superior to the use of white fluorescent lamps at the same light intensity (40 μmol m−2 s−1). Shoots treated with compressed air for immersion and additional gas exchange during the culture period in the glass vessel of TIS systems resulted in higher propagation rates and a larger number of shoots harvested as well as a larger number of roots formed per shoot after the 7-wk culture period.