HIGH-FREQUENCY PLANT-REGENERATION FROM PROTOPLASTS OF INDICA RICE (ORYZA-SATIVA L) USING MALTOSE

Plants were regenerated from indica rice (Oryza sativa L. cv. IR43) protoplasts isolated from mature embryo-derived cell suspensions. Cultured protoplasts divided and formed colonies in R2, as well as in N6-based nutrient media. Nurse culture increased colony formation from protoplasts. Unselected callus colonies transferred to regeneration media readily produced green plants. Regeneration frequency increased 8 to 12-fold when maltose was used in place of sucrose as a carbohydrate source. Of the three basal regeneration media compared, R2 medium was found to be more effective than MS or N6 medium in producing plants. A plant regeneration frequency of 70 to 77 % was obtained in the R2 medium which contained 5 mg/L K, 1 mg/L NAA, 30 g/L maltose, and 8 g/L agarose. Over 3000 plants were regenerated from protoplast-derived calli, and 1000 of these were grown in soil for the evaluation of plant phenotype.