Effect of culture media and conditions on callus induction and plant regeneration of Malaysian wild rice Oryza rufipogon IRGC 105491

An efficient and simple method for high frequency regeneration from mature seeds of wild red rice (Oryza rufipogon) is described. The medium composition most suitable for embryogenic callus induction was identified to be Murashige and Skoog (MS) media with 2.5 mg/l 2,4-Dichlorophenoxyacetic acid, 0.1 mg/l Kinetin, 3 g/l Proline, 25 mg/l Glutamine and 30 g/L sucrose (CIM 12) which gave a callus induction rate of 76%. The addition of Glutamine (25 mg/) to callus induction media resulted in a higher embryogenic callus induction frequency in MS (up to 76%) compared to N6 media (68%). Murashige and Skoog media produced a higher rate of callus induction under continuous dark conditions whilst N6 media produced a higher rate of callus induction under continuous light conditions. The maximum regeneration frequency (68%) was observed when 28 days old MS medium friable embryogenic calli were cultured on N6 medium supplemented with 3 mg/l 6-benzylaminopurine, 1 mg/l naphthaleneacetic Acid. N6 media produced a higher rate of regeneration than Murashige and Skoog media. The elongated shoots were rooted efficiently upon transfer to half strength Murashige and Skoog basal medium. Rooted plantlets were successfully transferred to soil after hardening with 96% survival rate. The regenerated plants were fertile and developed normally.