Differential genotypic and growth regulators response in androgenesis of rice (Oryza sativa L.)

Effect of genotype, pollen developmental stage, synthetic plant hormones in influencing androgenesis of rice were assessed. Response regarding androgenic callus induction as well as green plantlet regeneration was superior in the genotype Rajshree in comparison with other genotypes like Sita, Jaya and Kanak. It was observed that the late uninucleate stage of pollen development is the best for calli formation from cultured anthers of rice. Among the growth regulator tested, MS medium fortified with 1.5 mg l⁻¹ 2, 4-D was most encouraging for callus induction and proliferation. However, regeneration medium supplemented with BAP (1.5 mg l⁻¹), NAA (0.5 mg l⁻¹) and KIN (2.0 mg l⁻¹) was found to be the most suitable for green plantlet regeneration. For root induction and elongation, MS medium fortified with BAP (2.0 mg l ⁻¹) and NAA (0.5 mg l⁻¹) performed most dynamically. In vitro generated androclones were successfully acclimatized. The callus cytology showed the presence of different levels of cytodifferentiation and variant cells among the regenerated plants.