Micropropagation and callus induction of rice (oryza sativa l.) varieties MR 219 and MR 253 / Nazatul Asikin Muda

Two local Malaysian rice varieties, MR 219 and MR 253 were examined for their in vitro regeneration and callus induction responses using mature seeds, leaf disc, stem, internode and root sections obtained from in vitro seedlings. After 4 weeks of culture, the optimum in vitro regeneration of MR 219 (100%) and MR 253 (100%) were recorded from internode explant cultured on MS media supplemented with 2.0 mg/L BAP and 0.05 mg/L NAA and MS media supplemented with 1.0 mg/L BAP and 0.5 mg/L NAA respectively. Other explants failed to regenerate in vitro. In general, rice variety MR 253 showed better in vitro regeneration than MR 219. Callus growth from seed, stem, intemode and root explants became visible after 1-2 weeks being cultured on MS medium supplemented with various concentrations of 2,4-D. The highest callus induction frequencies for MR 219 (100%) and MR 253 (100%) were both obtained from rice seed explant cultured on MS media with 1.5 mg/L 2,4-D. Based on the overall result obtained, rice variety MR 219 gave better callus induction response than MR 253 in terms of callus induction frequency, size and the morphological characteristic of calli induced. Plantlets of MR 219 and MR 253 were successfully acclimatized and transferred onto different planting media. The highest rate of plantlet survival of MR 219 (100%) and MR 253 (60%) during acclimatization was recorded on the mixture of cocoa peat vermiculite and cocoa peat zeolite planting media respectively.