Effect of Low Temperature Pre-Treatment on Anther Culture in Selected Indica, Japonica Rice Varieties and their Inter Sub-Specific Hybrids

Abstract

Effect of cold pre-treatment of panicles with reduced temperatures (of 5°C, 7°C, 8°C and 10°C) and exposure for different time durations (at weekly intervals up to 4 weeks) on anther culture of Japonica rice variety Hu lo tao, Indica rice varieties Bg 90-2, Bg 379-2 and their F1 hybrids for high frequency callus induction and plant regeneration was investigated. Anthers were cultured in N6 medium with 5% sucrose, 2 mg l-1 2,4 D and 0.5 mg l-1 Kinetin. The cultures were kept in the dark at 28 ± 2°C for callus induction. Induced calli of 1-2 mm diameter were transferred to half strength Murashige and Skoog (MS) medium supplemented with 2.0 mg l-1 Kinetin and 0.5 mg l-1 NAA. The effect of variety and cold pre-treatment was significant at 5% probability level. The Indica varieties had the lowest callus induction frequency (0.3% - 7.0%). Japonica and Japonica × Indica hybrids had high callus induction (12.3% - 70.0%). The F1 hybrid Hu lo tao × Bg 90-2 had comparatively high callus induction (31.0% - 70.0%) than the other genotypes. Japonica variety Hu lo tao and F1 hybrids had highest callus development at cold pre-treatment at 8°C for 14 and 21 days. The highest green plant regeneration was observed in F1 hybrid, Hu lo tao × Bg 90-2 followed by Japonica variety subjected to 8°C for 14 days. Very poor green plant regeneration was observed in Indica variety, Bg 90-2 when it was exposed to 7°C for 21 and 28 days. Variety Bg 379-2 did not produce any green plant at any treatment. The F1 hybrid Hu lo tao × Bg 379-2 produced lower green plants than F1 hybrid Hu lo tao × Bg 90-2. Cold pre treatment at 8°C temperature for 14 days was found to be most effective for anther culture in experimental genotypes used in the study. Key words: variety, cold pre-treatment, callus induction, plant regeneration, rice DOI: 10.4038/cjsbs.v38i1.1322 Cey. J. Sci. (Bio. Sci.) 38 (1): 11-16, 2009