Two-line Hengyou 1 (Hengnong S-1×Minghui63),a promising two-line hybrid rice com- bination, was chosen as one of the important crop varieties (or combinations)to extend in 1992. Based on 3 year experience, the te...Two-line Hengyou 1 (Hengnong S-1×Minghui63),a promising two-line hybrid rice com- bination, was chosen as one of the important crop varieties (or combinations)to extend in 1992. Based on 3 year experience, the technique of its summer season seed production was summarized and introduced. Hengnong S-1 is a thermo-sensitive genic male sterile (TGMS)line and the sensitive stage is during 10- 15days before heading. During the sensitive stage,if the daily lowest temperature is below 22℃for 3 consecu- tive days or the temperature is lower than 22℃ for 24 hours, the line will become fertile. Therefore,a desir- able time should be selected for seed production. In the sounthern part of Hunan province,the favourable flowering - time for seed production is on 15-20 July; The seeding interval of parental lines can be deter- mined mainly by the method of leaf number difference; The male parent should be seeded only one time with two stepsseedling raising,and the proper row ratio is 2:14 with "Wide Double Rows"of male parent.展开更多
文摘Two-line Hengyou 1 (Hengnong S-1×Minghui63),a promising two-line hybrid rice com- bination, was chosen as one of the important crop varieties (or combinations)to extend in 1992. Based on 3 year experience, the technique of its summer season seed production was summarized and introduced. Hengnong S-1 is a thermo-sensitive genic male sterile (TGMS)line and the sensitive stage is during 10- 15days before heading. During the sensitive stage,if the daily lowest temperature is below 22℃for 3 consecu- tive days or the temperature is lower than 22℃ for 24 hours, the line will become fertile. Therefore,a desir- able time should be selected for seed production. In the sounthern part of Hunan province,the favourable flowering - time for seed production is on 15-20 July; The seeding interval of parental lines can be deter- mined mainly by the method of leaf number difference; The male parent should be seeded only one time with two stepsseedling raising,and the proper row ratio is 2:14 with "Wide Double Rows"of male parent.
