谷子中矮秆资源创制、遗传解析和育种利用

Development,genetic deciphering,and breeding utilization of dwarf lines in foxtail millet

谷子是旱作生态农业的主栽作物和应对气候变化的战略储备作物,也是新时期功能基因研究的模式作物。谷子品种的中矮秆化是产业发展的必然趋势。国内外目前已报道的谷子矮秆材料达70多个,从形态上谷子矮秆种质可以分为叶穗直立的紧凑型和叶穗下披的常规型2类;赤霉素(GA)敏感性测定发现4个材料对GA不敏感,其他均是GA敏感型;显隐性分析表明,多数矮秆材料为隐性单基因控制,但矮88株高为多基因控制。利用自然群体关联分析和双亲杂交分离群体合计发掘了109个控制株高的QTL,精细定位了7个矮秆基因,半显性矮秆材料84133的矮化基因SiDW1是唯一克隆并进行功能分析的矮化基因。对谷子中矮秆品种选育的梳理表明,利用矮88和其衍生系为亲本已培育出139个中矮品种(系),实现了谷子株高的显著矮化,满足了机械化收获对抗倒伏降株高的要求。本文综述了国内外谷子株高矮化基因的研究进展,梳理了已经定位和克隆的谷子矮秆基因,讨论了谷子矮秆遗传和育种研究中的问题,展望了未来发展方向。

Foxtail millet(Setaria italica)is an important cereal crop in northern China’s arid and semiarid dry land agriculture,which has recently been proposed as a novel model for functional genomics.Breeding dwarf varieties is the development trend of foxtail millet industry.To date,more than 70 foxtail millet dwarf lines have been developed and reported worldwide.According to morphological characteristics,foxtail millet dwarf lines can be divided into two types:compact type with erect leaves and conventional type with droopy leaves.Gibberellins(GA)sensitivity assay indicated that four materials were not sensitive to GA and the others were sensitive.Genetic analyses detected that most of the dwarf phenotype lines were controlled by recessive genes,but the height phenotype of Ai 88 was controlled by multi-dwarf-gene.So far,79 QTL related with plant height regulation were detected by natural population GWAS or linkage analysis.Among seven genes or QTL fine mapped in foxtail millet,the semi-dominant dwarfism gene SiD1 in 84113 was the only one cloned and functionally characterized.In the history of breeding dwarf foxtail millet variety,Ai 88 was a backbone line,which had been utilized to develop 139 cultivars with reducing plant height to meet the requirement of logging resistance and mechanized harvest.In this study,we reviewed systematically the research progress of dwarfing gene in foxtail millet,sorted out the dwarfing genes that had been located and cloned,discussed the problems in the research of dwarfing genetics and breeding,and prospected the future development in foxtail.