Effect of Genotype and Growth Regulators for the Callus Initiation and Regeneration of Mustard (Brassica napus)

Abstract

 The present study is conducted to develop an efficient protocol for shoot and plant regeneration using four cultivars grown under the agricultural conditions of Bangladesh. Seed explants from four varieties were cultured in vitro and callus formation and swelling as well as the mode of shoot and root regeneration was evaluated. A highly positive response to in vitro culture, i.e., callus formation or swelling, was observed in all the varieties tested. Effect of two different callusing media (2 mg/L and 3 mg/L 2, 4-D with 2 mg/L BA) and shoot regeneration media (2 mg/L and 3 mg/L NAA with 2 mg/L BA) and for root (1 mg/L IBA and 1 mg/L NAA) were used for callus induction and regeneration of four cultivars of Brassica napus, viz., Hoiro, Rye, Shewto Sarisa and Tori-7. Parameters like callus formation and number of shoots and roots per explants were highly variable among genotypes. A high frequency of callus was obtained in the variety Tori-7 (83.33%) seed followed by Shewto Sarisa. Between the two concentrations, 2 mg/L of 2, 4-D showed the highest number of callus. 100% shoot regeneration was seen in Rye in the concentration of 2 mg/L BA with 3 mg/L of NAA. The shoots were then rooted and best results were obtained on media having 1 mg/L of IBA in MS medium. Rooted plantlets were successfully established into the soil. The developed system relies on somaclonal variation for further research and the high regenerative capacity of seed explants of B. napus cutivar.