超级稻增产基因的聚合及分子设计育种利用研究

Yield trait, a complex quantitative trait, is controlled by multiple genes and environments. 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, NIL and SSSLs derived from some elite rice varieties Liang-You-Pei-Jiu (LYP9, Peiai64×9311), Ninggeng 4, ZH498 and Tian-You-Hua-Zhan, map-based cloning strategy would be further used to isolate 2-3 high yield genes and heterosis, and to dissect the molecular mechanism and genetic network of these genes. Some key yield genes such as GL7, GS2, IPA1, DEP1, NAL1, gn1a, gs3, GW5, gw7 and Ghd8 via backcrossing will be introgressed into the mega rice cultivars. 9311, Ninggeng 4, TYHZ and ZH498 near isogenic introgression lines containing the various target genes will be constructed. Multi-gene pyramiding lines and gene-phenotype (GP) database will be constructed too. We also analyze interaction relationship between the genes controlling the three components 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, multi-generations and in different environments, and to select the strongest gene pyramiding lines / strain and the optimum polymerization pathway of yield genes. It is beneficial to breed by design new-generation super rice, to enrich and develop the theory of molecular design breeding.

产量性状是受多基因和环境控制的复杂数量性状，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。本项目利用水稻主栽品种（两优培九、蜀恢498、宁粳4号和天优华占等品种）衍生的遗传群体（RIL、NIL、SSSL），发掘一些具有育种利用价值的产量优异等位基因，解析产量性状形成的遗传基础及其调控网络。同时，将已克隆的增产基因GL7、GS2、IPA1、DEP1、NAL1、gn1a、gs3、GW5、gw7和Ghd8等，回交导入到主栽品种中，构建含目标基因的近等基因系和导入系文库；构建多基因聚合系的基因型-表型值（GP）数据库。在不同生态区预测多基因多世代的基因型效应值和目标基因型概论；选择最佳多基因聚合系和基因聚合途径，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。

构建了超级稻主栽品种9311/培矮64、蜀恢498和宁粳4号等代换系或SSSL文库6套，为重要性状的分子遗传机理解析和设计育种奠定了材料基础。系统揭示了水稻SBM1-OsMPK6模块、miR167a-OsARF6-OsAUX3模块、qTGW29311和qPND1-gn1aR498-SCM2-SCM3模块的调控网络增产机制。并将20多个已克隆的IPA1、DEP1、GW5L、Gn1a、gw8等基因导入主栽品种，建立了产量相关基因的基因型-表型G-P数据库和分子设计育种的技术平台。同时，将系列优质、高产基因导入9311、蜀恢498、宁粳4号背景的SSSL，预测多基因型效应值，选择最佳聚合系，培育新品种。已发表论文7篇，培养博士后1名、研究生7名，嘉禾优5号、京粳8号和川康优6308等6个品种通过国家或省级新品种审定。