Studies on Breeding and Application of Thermo- sensitive Genic 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 ability 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 overyidded more than 20%, reaching the significant level of 1% ; and arrrmg 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, siliquae 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. Amnng 8 agronomic traits, total siliquae per plant and seed yield of single plant were regarded as the key selecting indexes accccding to the correlation analysis between yield and the agronomic traits on heterosis and on the GCA effect of all parents.

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

Augmented randomized complete block test was conducted to evaaltuate the he terosis of 80hybrid combinations from TGMS line 402S and its original parent Xiangyou 91S, and thecombining ability of 40 testcrossing lines. The results of identification test showed that anong 47 combinationsyielding 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 combination s yielding overt heir corresponding higher yield parents, 18 ones with 402S and 9 ones with Xianyou 91S oveeryelded at 5 % or 1% significan: level The test for the GCA effect of all parents indicated t hat 402S possessed a stronger combining ability than Xiangyou 91S on yield, siliquae of main inflorescerce, total siliquae per plant, seed yield of single plant and 1000 - seed weight. 10 testcrosing lines with high GC A wer picked out for next testcrosses. Among 8 agronomic traits, total siliquae per plant and seed yield of single plant were regiarded as the key selecting indexes according to the correlation analsis between yield and the agronomic traits on heterosis and on the GCA effect of all parents