The effect of BA (6-benzyladenine) and coconut water on the growth of variegated red duckweed (Alternanthera reineckii ‘rosanervig’) in vitro

Abstract

This study investigated the effects of cytokinin on the growth of red duckweed Alternanthera reineckii ‘rosanervig’ using tissue culture techniques. Explants from the bud and stem sections were cultured on MS (Murashige and Skoog) medium supplemented with the growth regulator BA (6-benzyladenine) at concentrations of 0, 1, 2, and 4 mg/L, combined with coconut water at 0%, 10%, and 15%, resulting in 12 experimental conditions. Tissue cultures were maintained in a controlled environment at a temperature of 25±2°C with a light intensity of 3,000 lux for 8 hours per day over 28 days. The results revealed that the addition of 10% coconut water combined with BA at 1, 2, and 4 mg/L did not significantly increase the average number of leaves per plant (p>0.05) (23.33±9.79, 22.83±9.91, and 27.83±2.48 leaves per plant, respectively). Furthermore, the addition of coconut water at 0–15% and BA at 0–4 mg/L had no significant effect on leaf length or plant height (p>0.05). Coconut water at 10% alone induced the highest number of roots (10.33±4.03 roots) and root length (1.13±0.32 cm). The medium supplemented with 10% coconut water and 4 mg/L BA resulted in the highest number of shoots (8.00±2.61 shoots per plant). However, morphological evaluation revealed that these shoots appeared as callus-like structures, with stunted growth and poorly developed roots that did not adhere well to the medium. In contrast, plants grown on medium supplemented with 10% coconut water alone exhibited robust roots, bright red leaves, and smooth, non-brittle foliage. Therefore, the optimal tissue culture condition for propagating A. reineckii ‘rosanervig’ under aseptic conditions for export purposes is the use of 10% coconut water as a growth regulator in MS medium.