EFFECT OF COLD PRETREATMENT ON IMPROVING ANTHER CULTURE RESPONSE OF RICE (Oryza sativa L.)

Present study was designed to evaluate the effect of cold pretreatment temperatures (4, 8 and 12(degrees)C) and durations of treatment (5, 9 and 13 d) on anther culture efficiency among 13 genotypes. Anthers were cultured on N6 medium supplemented with 2, 4-D (2 mg/L) and Kinetin (0.5 mg/L). Anther inoculated media petri dish were incubated in the dark at 25 +/- 1(degrees)C for callus induction. When calli were 1-2 mm in diameter, they were transferred to MS regeneration medium supplemented with Kinetin (1 mg/L), NAA (1 mg/L) and BAP (2.5 mg/L) and were incubated at 25 perpendicular to 1(degrees)C under 16 h/8 h light/dark condition. The cold treatment at 12(degrees)C for 5 days was found to be the most effective in all experimental genotypes used for the study. Out of 13 genotypes evaluated, IR58025B (25eB) was highly responsive for both callus induction as well as green plant regeneration.