Protocol optimization for rapid and efficient callus induction and in-vitro regeneration in rice (Oryza sativa L.) cv. CO 51

Abstract

CO 51 is a recently developed semi dwarf, short duration variety of rice popularly grown in Tamil Nadu. Optimization of tissue culture protocol for the variety was one of the most important steps required; in order to make the variety suitable for genetic transformation and gene editing techniques. Immature embryos of CO 51 have been used as explant for callus induction. The immature embryos were cultured on callus induction media (NB media) containing Naphthalene Acetic Acid (NAA) 1 mg l-1, 6-Benzylaminopurine (6-BA) 1 mg l-1 and various concentrations of 2,4 Dichlorophenoxy acetic acid (2,4-D). NB media supplemented with 2.5 mg l-1of 2,4-D have been found to show the highest callus induction frequency that is 94.4%. The calli showing desired features were transferred from NB media to pre-regeneration media (NB-PR) having 2,4-D (2 mg l-1), 6-BA (1 mg l-1 ), NAA (1 mg l-1) where the calli tuned golden- yellow. These calli were then transferred to regeneration media (RNM media) supplemented with 6-BA (3 mg l-1) along with various concentrations of NAA. RNM media with1 mg l-1 NAA showed the highest frequency of shoot induction that is 72.2% with an average of 12 shoots per callus.

Keywords

• co 51
• callus induction
• in-vitro regeneration
• 2
• 4-d
• naa
• 6ba