Optimization of in vitro culture system in tropical Japonica and Indica rice (Oryza sativa L.) genotypes

Abstract

The plant growth regulator (PGR) effects on callus induction frequency (CIF) and plantlet regeneration were studied on four rice genotypes. Mature seeds were used as explant for callus induction in different combinations of 2, 4-D, Kn and NAA using MS and N6 medium. The maximum CIF recorded was 86.0% (Azucena) and 83.3% (Palwan) in N6 media augmented with 2,4-D, Kn and NAA at 2.5, 0.5 and 1.0 mg/L, respectively. In genotypes CB174R and CB87R, 66.7% and 71.6% CIF were obtained in N6 media supplemented with 2,4-D, Kn and NAA at 2.0, 0.25 and 0.5 mg/L, respectively. In MS medium a total plantlet regeneration of 70% was observed in Palwan and 10% in CB174R augmented with NAA (0.5 mg/L) + BAP (1.0 mg/L) + Kn (0.5 mg/L) and NAA (0.5, 1.0 mg/L) + BAP (0.5, 1.0 mg/L) + Kn (0.5, 2.0 mg/L), respectively. The efficiency of plantlet regeneration depended on genotype, media constituents and PGR.

Keywords

• rice
• embryo culture
• callus induction
• regeneration
• callogenesis
• rhizogenesis