GA_3 Spraying Dosage for eui TGMS Rice Changxuan 3S in Its Hybrid Seed Production

[Objective]Changxuan 3S was thermo-sensitive genicmale sterile(TGMS)rice selected from irradiated seeds of 64S by 350 Gy60Coγ-ray.The aim was to confirm GA3 spraying dosage of Changxuan 3S with eui gene in its hybrid seed production.[Method]Changxuan 3S possessing eui gene and its parent 64S were chosen as materials.Comparison studies on sensitivity to GA3 in their hybrid seed production were carried out.[Result]The suitable stage for spraying GA3 in the hybrid seed production of Changxuan 3S was at 10% of panicles headed;The optimal dosage was 90 g/hm2 with 2 split sprayings,the first spraying of 45 g/hm2 at heading of 10% panicles and the second one of 45 g/hm2 on the following day.Under the condition of spraying GA3 at the rate of 90 g/hm2,the panicle neck exsertions of Changxuan 3S was +1.78 cm,and exserted stigma rate and seed setting rate of Changxuan 3S were 96.87% and 36.44%,being 21.46% and 16.33% more than those of Peiai 64S/9311,respectively.The theoretical yield of Chuangxuan 3S/9311 reached 2 931.90 kg/hm2,which was increased by 1 259.40 kg/hm2 comparing with Peiai 64S/9311.[Conclusion] Compared with 64S,Changxuan 3S is more sensitive to GA3,which results in no or little using GA3 in seed production of Changxuan 3S.Moreover,Changxuan 3S showed higher yield potential than 64S.