Studies On Methods Of Breeding Iso-cytoplasmic Restorer Lines In Japonica Hybrid Rice (Oryza Sativa L.)

Parental lines are a key part of hybrid rice breeding. It's worth studying that iso-cytoplasmic restorer lines of Japonica hybrid rice breeds through method of maize breeding. This thesis concludes two parts below: 1.Study on effect of different crossing ways on breeding iso-cytoplasmic restorer lines4 single cross hybrid were derived from crossing of 4 CMS lines and 3 restorer lines; 6 double cross hybrid from crossing of four single cross hybrid each other ; 8 three way cross hybrid from crossing of four single cross hybrid and 3 restorer lines .Total is three cross way, which include 18 populations. Breeding effect of crossing ways is compared with each other, judged by mean of GCA of iso-cytoplasmic restorer lines and frequency of fine iso-cytoplasmic restorer lines. Results showed that single cross way is more efficient than others. 2.Study on selecting way of GCA in the three crossing waysExperiment was done with 18 populations of three crossing ways above, and results show:(1) Yield of single cross hybrid is correlated positively with yield of its iso-cytoplasmic restorer lines, and correlation coefficients, 0.894 , is significant at the level of 0.05; yield of iso-cytoplasmic restorer lines is correlated positively with its yiejd of test-cross Fl, and correlation coefficients , 0.879 , is significant at the level of 0.05 . In conclusion, selecting of GCA is in according with selecting of agronomic traits in the single crossing way.(2) High yield's population from single cross way lead possibly to fine iso-cytoplasmic restorer lines.(3) Results in three crossing ways all show that GCA's effect of restorer lines in basic populations contributes more to GCA of its Iso-cytoplasmic restorer lines .