Studies on the effect of natural extract of some marine algae on in vitro growth and development of banana micropropagules

Abstract: The current work aims to provide a cost-effective and reliable micropropagation method of banana using some natural extract of unexplored potential seaweeds. We tried natural extract of eight different seaweeds (C. racemosa, Gracilaria edalis, Caulerpa paspaloides, Ulva lactuca, Sargassum tenerrimum., Caulerpa sertularioides, Sargassum wightii, Gracilaria corticata.) to check their role in in vitro growth and development of micropropagules and their potential in replacing commercial plant growth regulators (PGRs) in banana micropropagation. The in vitro developed shoots were allowed to grow on modified MS medium supplemented with different seaweed extracts and regularly subcultured on the same medium throughout the experiment. The growth and biochemical parameters were recorded and compared with micropropagules growing in a controlled environment (i.e., MS medium supplemented with/without standard PGRs). We found a significant increase in shoot length (highest in S. tenerrimum, i.e. double as compared to negative control), shoot number (highest in G. edalis, i.e., three fold as compared to negative control) and fresh weight (S. tenerrimum) of the banana micropropagules when grown under the influence of Liquid Seaweed Extract (LSE). This is comparable to growth observed in standard control conditions (i.e. positive control). However, addition of LSE of G. corticate, C. paspaloides and S. wightii did not show any noteworthy effect on shoot length, shoot number and fresh weight. Total chlorophyll and other biomolecule accumulation in test propagules varied with types and concentrations of LSE. S. tenerrimum proved to be overall good growth promoter, as it caused maximum accumulation of chlorophyll (0.202±0.02 mg g^-1) and protein (105±0.45 mg g^-1) and significant and encouraging results in phenol, carbohydrates and proline. Our results show that seaweed can be potential source of beneficial natural compounds and it can be a cheaper option in banana micropropagation technology.