In vitro culture of panicle has been the method to accumulate starch and protein in immature grains by providing nutrients after florets crossed between remote genotypes artificially. Grain filling means embryo development and sucrose translocation from photosynthetic source, and starch manufacture in endosperm. The concentrations of sucrose used to culture immature rice panicle were 5, 10, 15, 20% and glutamine was 20 mM. When immature rice panicles at 5 days after flowering were cultured in distilled water with different concentrations of sucrose, glutamine 20 mM and MS medium with different concentrations of sucrose, glutamine 20 mM for 30 days the later was effective on grain filling. The optimal concentration of sucrose on grain filling in vitro culture of rice panicle was 10% and the weight of grain cultured was 10.14 mg that was corresponded to 57% of intact plant. In the method of treating plant growth regulators, the culture of immature rice panicle adding in MS medium with Kinetin, IAA, ~textrmGA3 were effective on grain filling than the culturing of immature rice panicle after submerging in solutions of Kinetin, IAA, ~textrmGA3 for 1day. When immature rice panicle was cultured in MS medium with sucrose 10% and Kinetin 46.47 ~mu M it was effective on grain filling, respectively. The weight of grain cultured was 13.1mg that was corresponded to 75% of intact and germination rate was 51 %. When immature rice panicles were cultured in medium with different concentrations combined with Kinetin 4.65, 46.47, 464.7 ~mu~textrmM , IAA 5.71, 57.08, 570.80 ~mu~textrmM for 30 days and in medium with IAA 5.71, 57.08, 570.80 ~mu~textrmM for 15 days after culturing in medium with Kinetin 4.65, 46.47, 464.70 ~mu~textrmM for 15 days the effect on grain filling was similar.

• Seung Hun Lee
• Ho Jin Lee