基于“多基因聚合-早世代组配”策略的水稻分子改良研究

传统水稻育种技术最主要瓶颈是选择效率低和周期长。为了提高水稻优异材料选育和杂交稻组配效率,创新水稻分子育种策略,利用分子标记辅助选择多基因聚合和早世代杂交组配,展开水稻恢复系分子改良和杂交新组合的调查评价。供体亲本H318与恢复系亲本华占进行杂交,通过选择和设计关键有利基因的分子标记,利用毛细管电泳基因分型技术,将Wxb、fgr、Xa23、Pi2、Pi46以及Pita 6个稻米品质、香味、抗白叶枯病和抗稻瘟病相关功能基因进行聚合利用。通过多世代的田间生物学性状调查,米质、抗性等表型鉴定,获得14份以恢复系华占为遗传背景,目标基因纯合的优质、双抗和香型稳定的水稻株系。依据材料稳定遗传特性,将改良后代株系与生产应用的不育系进行测配和组合的调查评价,筛选获得潜在优良杂交稻。在育种进程中采用"多基因聚合-早世代组配"策略,实现多个有利基因快速聚合,定向改良稻米品质和抗病性等关键性状,并且促进杂交水稻组合的高效选育。

Molecular Improvement Based on the Strategy of ′Multiple Genes Pyramiding-early-generation Hybridized Combination′ in Rice

Low selection-efficient and long cycle are the main bottle necks of conventional breeding technique.In order to make improvement of the efficiency of variety breeding and hybridized-combination,we innovated the molecular breeding strategy in rice.Then we carried out molecular improvement of restorer line and evaluation of new hybrid combination by multiple genes pyramiding and early-generation hybridized combination.The donor parent H318 was hybridized with restorer parent Huazhan,and we constructed the multiple genes pyramiding technology by selection and design molecular markers,and performed pyramiding-improvement application with 6 functional genes for grain quality,fragrance,and disease resistance,including Wxb,fgr,Xa23,Pi2,Pi46,and Pita.As the result,we achieved a series of 14 stable rice lines with genetic background of restorer line Huazhan,homozygous target-genes,and high grain-quality,double-resistant,and fragrance.In accordance with stable-inheritance properties,ideas of early-generation hybridized combination was raised.Test cross of improved lines with CMS lines in production practice of NingA and C815S were carried out,and performance of new hybrid combination was evaluated,therefore,potential superior hybrid rice was screened and achieved.In this study,breeding programs adopted the strategy of multiple genes pyramiding-early-generation hybridized combination,this method could realize the quick pyramiding of multiple favorable genes,targeted improvement of key traits of grain quality and disease-resistant,promotion of high-efficiency breeding of hybrid rice.