Effect of Plant Growth Regulators on Callus Induction of Black Rice (Oryza sativa L.)

Aims: Black rice of Manipur is known for its aroma and nutritional quality. As per the reports on tissue culture of rice, callus induction response of traditional cultivars was much lower than the modern high yielding varieties. Considering the importance of the black rice, and effort was taken to standardized callus induction protocol of black rice of Manipur.

Study Design: Complete Randomized Design.

Place and Duration of Study: Department of Seed Science and Technology, Faculty of Agriculture, Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar 736165, West Bengal, India, between June 2020 and July 2023.

Methodology: Mature seeds of two black rice varieties used in this work. The seeds were dehusked manually, washed with running tap water. Then sterilized with 1% bavistin and again washed with running tap water. Seeds were surface sterilized with 0.2% HgCl2 for 15 minutes. Sterilised seeds were rinsed with sterile distilled water inside laminar air flow hood. The seeds were blotting dry using autoclaved tissue paper and sterile seeds were cultured with the scutellum pointing up wards on callus induction medium fortified with different concentrations and combinations of plant growth regulators.

Results: MS medium fortified with 2,4-D was found to be better than picloram and TDZ to induce callus and the 2,4-D @ 1.00 mg/L and 2,4-D 2.00 mg/L was found to be the best concentrations. Callus health was also good when MS medium invigorated with 2,4-D.

Conclusion: An efficient embryogenic callus induction and plantlet regeneration protocol for black rice was established by using mature seeds. In callus induction studies, with different concentrations of PGR, 2,4-D, higher callus induction frequency was observed with 1.00 mg/L 2,4-D and 2,4-D @ 2 mg/L for both rice varieties.