Studies on 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 Peiai 64S by 350 Gy^（60）Coγ-ray.The aim of the study 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 Peiai 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,respectively.The theoretical yield of ＂Changxuan 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 Peiai 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 Peiai 64S.

Studies on Breeding and Application of Thermo-sensitive Genie Male Sterile Line 402S in Brassica napus Ⅰ. Hie Breeding Procedure and Character of 402S

A new rapeseed TGMS line 402S has been bred through six years with seven generations by hybridization and systematic breeding.402S possesses the similar thermo-sensitive male sterility to its female parent Xiangyou 91S which performed fertile,partially sterile and sterile throughout the flowering stage,and resembles its male parent Zhongshuang 4 on agronomic traits.And 402S has the double-low (low erutic acid and low glucosinolate) quality like its original parents.

Studies on Breeding and Application of Thermo-sensitive Genie Male Sterile Line 402S in Brassica napus Ⅱ.Evaluation of Heterosis and Combining Ability

Augmented randomized complete block test was conducted to evaluate the heterosis of 80 hybrid combinations from TGMS line 402S and its original parent Xiangyou 91S,and the combining a-bility of 40 testcrossing lines.The results of identification test showed that among 47 combinations yielding over the control Xiangyou 15,17 ones with 402S and 3 ones with Xiangyou 91S overyielded more than 20%,reaching the significant level of 1 %;and among 51 combinations yielding over their corresponding higher yield parents,18 ones with 402S and 9 ones with Xiangyou 91S overyielded at 5% or 1% significant level.The test for the GCA effect of all parents indicated that 402S possessed a stronger combining ability than Xiangyou 91S on yield,ailiquae of main inflorescence,total siliquae per plant,seed yield of single plant and 1000 seed weight.10 testcrossing lines with high GCA were picked out for next testcrosses.Among 8 agronomic traits,total siliquae per plant and seed yield of single plant were regarded as the key selecting indexes according to the correlation analysis between yield and the agronomic traits on heterosis and on the GCA effect of all parents.