超级稻增产基因的聚合和分子设计育种研究

Molecular design breeding of ideotype super rice using increasing-yield genes is an important research direction of the breakthrough of rice yield bottleneck. In this study, based on deep resequencing RILs of a pioneer super rice Liang-You-Pei-Jiu (LYP9, Peiai64×9311), and the new developed and national authorized cultivar Guang-Liang-You7203, map-based cloning strategy would be further used to isolate 2-3 high yield genes and heterosis, and to dissect the molecular mechanism of these genes. Some key yield genes such as IPA1、DEP1、Gn1、GW8 and Ghd8 via backcrossing will be introgressed into the super-rice restorer cultivars 9311 and R7203, respectively. 9311 or R7203 near isogenic introgression lines containing the various target genes will be constructed. Multi-gene pyramiding lines and geno-phenotype (G-P) database will be constructed too. We also analyze interaction relationship between the genes controlling the three compenents of yield (panicle number, grain number and grain weight), to elucidate the regulation patterns of yield. Using breeding value prediction program QuLine and CrossPredictor, to predict the target genotype effects under polygenes and multi-generations, and to select the strongest gene pyramiding lines / strain and the optimum polymerization pathway of yield genes. To breed by design new-generation super rice, to enrich and develop the theory of molecular design breeding.

利用增产基因分子设计培育理想株型超级稻是突破目前水稻产量瓶颈的重要方向。本研究利用我们已深度测序的超级稻两优培九RIL群体的信息以及新选育的国审品种广两优7203，进一步剖析水稻产量基因和杂种优势分子遗传机理。同时，将已克隆的增产基因IPA1、DEP1、Gn1、GW8和Ghd8等基因，回交导入到超级稻亲本9311和R7203恢复系中，构建9311或R7203遗传背景的含目标基因的近等基因系和导入系文库；构建2个以上基因聚合系的基因型-表型值（G-P）数据库。分析产量三因子（穗数、粒数和粒重）基因之间的互作关系，阐明其对产量的调控规律。利用育种值预测程序QuLine和CrossPredictor，预测多基因多世代的基因型效应值和目标基因型概论；选择最强优势的基因聚合系/品系和产量基因最佳聚合途径，分子设计培育新一代超级稻，丰富和发展分子设计育种理论。

利用我们克隆的等50 多个基因，逐个导入到不同生产稻区的主栽品种中，如R7203和9311等恢复系，构建多基因聚合系的基因型-表型值(G-P)关系，建立产量G-P数据库。目前已构建了9311背景的双基因的G-P数据库。构建了分子育种平台。利用育种值预测程序和开展分子设计育种研究。基于IPA1-DEP1的高产高效聚合效果，提出了理想株型与杂种优势相结合的未来超级杂交稻分子设计模型。分子设计选育了一系列调控水稻产量和品质的水稻新组合，优质的籼型水稻品种。研究成果发表在国际著名学术期刊《自然-植物（Nature Plants）》上。育成2个杂交水稻新组合广两优7217和嘉禾优7245,通过国家水稻新品种审定。发表研究论文4篇。