Analysis of heterosis and combining ability on the major characters of Huanghui No.7, a rice wide spectrum restorer line by space mutation

Hanghui No. 7, with strong restoring ability, were obtained by selection and analysis from rice Texianzhan 13, which were carried into space with retrieved satellite for 15 days. Stronger restoring ability were exhibited to three photoperiod-temperature sensitive genic male sterility lines (64S, N9S and N39S, etc.) and eleven cytoplasmic-nucleic male sterile lines of three-line (Hua A, Tianfeng A, II-32A, Bo A, Te A, Qiu A, Mei A,. etc.), and the combinations appeared power competition heterosis of F1 hybrid compared with the control Peizashuangqi, and the superior combination ratio of 1000 grain weight, the per panicle spikelets, filled grains per panicle, seed setting ratio, and panicle length were 100%, 74.3%, 85.7%, 71.4%,and 78.6% respectively. Fifty-four hybrids and their 15 parents (9 male sterile lines and 6 restorer lines ) were studied on the combining ability for 8 major agronomic characters. Crosses were made by NCII design.The result showed that Huanghuiqihao appeared a better general combination ability effect value on the grains weight per plant, filled grains per panicle, seed setting rate and 1000-grain weight than the other restorer lines. Furthermore, positive effect of the special combining ability on yield character were observed in 7 combinations of Huanghuiqihao. And three combinations of Huayouhuangqi, Chuanxiangyouhuangqi, Peizahuangqi exhibited higher yields than the other six combinations. Genetic analysis declared the agronomy characters.of plant height, panicle length and 1000-grain weight were controlled by the genetic factor mainly and were not easily affected by environment factors.The results indicated that Huanghuiqihao would be a useful material in the improvement of rice breeding. (author)