Moringa oleifera Lam., a tree naturally grown in the tropics, is becoming increasingly popular
as an industrial crop due to its multitude of useful attributes. Therefore, this study tested the
effect of temporary immersion system (TIS) bioreactors for mass micropropagation of Moringa oleifera
Lam. callus, roots, and shoots. TIS are tissue culture systems that make use of timers to periodically
immerse and drain plant cultures in a liquid nutrient medium instead of using solidified media. In
initial studies, Moringa oleifera seeds were germinated in vitro, and in vitro seedling leaflets were then
used as explant material for callus production on the pre-culturing media. Two experiments were
conducted to improve the protocol for TIS bioreactor production. The first experiment investigated
the effect of 6-benzylaminopurine (BA) and kinetin, whereas experiment 2 was conducted to improve
shooting production. For the first experiment, leaf material was cultured onto a solidified medium
consisting of half-strength Murashige and Skoog (MS) basal salts and 0.5 ppm 1-naphthaleneacetic
acid (NAA) to initiate callus production before splitting it between solidified media and bioreactors
for shooting. The shooting media consisted of full-strength MS basal salts and different treatments of
kinetin and BA. A significant increase in callus production was observed with the use of TIS bioreactors,
compared to solidified media, whereas root production had a highly significant interaction effect
between the media and the cytokinin treatments. With shoot proliferation in mind, experiment 2
was performed, where microcuttings from in vitro-grown seedlings were excised and cultured onto
a solidified MS medium, consisting of a control (0 ppm BA) and two different concentrations of
6-benzylaminopurine (BA) (0.1 ppm BA and 0.2 ppm BA) in the pre-culturing phase. Microcuttings
were again excised after two weeks and transferred to the shooting media containing 0.1 ppm BA
in TIS bioreactors and semi-solidified medium. Results showed TIS bioreactors to be effective in increasing both the amount and length of shoots produced. Shoot and callus fresh weights were
also higher in explants cultured in TIS bioreactors. The results of this study also suggest M. oleifera
sensitivities to plant growth regulators (PGRs). In conclusion, this study successfully produced callus,
roots, and shoots in both the solidified media and TIS bioreactors, emphasizing the prospect of using
TIS bioreactors for mass micropropagation of M. oleifera callus, roots, and shoots.The National Research Foundation (NRF) (Competitive program for Rated Researchers).https://www.mdpi.com/journal/agronomyam2023Plant Production and Soil Scienc
