Study On Possibility Of Utilization Of Indica Hybrid Rice Of Multiple-cytoplasm Resources

At present, 85% of all CMS cytoplasm deviated from native rice. Utilization of hybrid rice with single CMS resources is not only the limit factor for the improvement of yield per area, but also could cause to epidemic disease infecting single CMS cytoplasm. Diversity of CMS resources is the key to solve the problem. In the study, CMS lines and maintainer lines from 5 different type cytoplasm, namely YL-CMS( II 32A), AA-CMS (XinxiehuangA), WA-CMS (LongtepuA), G-CMS (Gang 46A), HL-CMS (YuetaiA), were used to develop 20 binary CMS lines, the binary CMS lines were hybrided with 9311, Kang65, Teqing, and 60 three-way cross hybrid were developed. Cytoplasmic effect on out-crossing characters, agronomic characters and disease resistance and difference of restorer-maintainer relation were investigated. The possibility of utilization of multi-cytoplasm hybrid rice was discussed. The result were as followed:1. YL-CMS, AA-CMS, WA-CMS, G-CMS can maintain the sterility each other, also don't change abortive type; 4maintainers II32B, XinxiehuangB, LongtepuB, Gang 46B can't maintain sterility of HL-CMS lines.2. Different cytoplasmic effect on out-crossing characters mainly show on exserted stigma of CMS lines. YL-CMS is excellent, next to G-CMS, AA-CMS and WA-CMS, HL-CMS .3. CMS lines with different cytoplasm show no difference on resistance to bacterical leaf blight disease .4. As to restorer ability, 9311 can only restore HL-CMS lines, Teqing and Kang 65 show similar to different type CMS lines. For restorability of different CMS type, HL-CMS is excellent, with average seed setting rate 67.49%; YL-CMS, AA-CMS, WA-CMS, G-CMS are of similar performance, with average seed setting rate 56.98%, 54.59%, 54.39%, 58.68%, respectively.5. On the condition that same CMS cytoplasmic background, restorability of CMS lines was also decided by special nucleus-cytoplasm interaction.6. As different CMS-type don't show significant effect on main out-crossing characters, main agronomic characters and disease resistance, breedingmulti-cytoplasm hybrid rice with same restorer-maintainer relation cytoplasm is possible.