越冬栽培稻产量性状相关QTL定位

越冬栽培稻是一类能越过自然冷冬季节并在第2年春季萌芽、正常开花结实、收获稻谷的水稻品种。本文通过对越冬栽培稻产量性状QTL分析,明确产量相关性状的遗传规律,旨在进一步解析越冬栽培稻产量性状的遗传机制,为育种创新利用提供理论依据。以3份越冬栽培稻构建的3个半同胞F2群体为材料。各考察15个产量相关性状,利用Excel 2003、GraphPad Prism 5.0和QTL IciMapping 4.10软件分析数据、绘制遗传图谱、定位QTL和联合分析。结果表明,产量性状表型值在3群体中呈连续正态分布,表现为数量性状遗传。共检测到37个QTL和26对上位性QTL,贡献率分别介于2.32%～36.31%和1.04%～2.05%;检测到9个同时影响2个及以上产量性状(一因多效)QTL标记区间;以联合分析检测到13个产量性状相关QTL,其中4个QTL区间与单群体检测QTL区间重叠;越冬栽培稻产量相关性状QTL以加–显性效应遗传为主、上位性遗传效应为辅。本研究将为越冬栽培稻产量相关基因挖掘及育种创新利用奠定基础。

Locating QTL controlling yield traits in overwintering cultivated rice

Overwintering cultivated rice is a type of special rice that can survive through cold-winter season, germinate in spring of the coming year, seed and be harvested. In this study, four genetic linkage maps contained 108, 116, 111, and 184 SSR markers were constructed using three half-sib F₂ populations from overwintering cultivated rice for the identification of QTLs affecting yield traits, respectively. Phenotypic values for yield traits were investigated for QTL mapping and other statistical analysis using Microsoft Excel 2003, GraphPadPrism 5.0, and QTL IciMapping 4.10. The phenotypic values for yield traits exhibited a continuously normal distribution and might be controlled by quantitative trait locus (QTL). A total of 37 QTLs affecting 15 yield traits and 26 epistatic QTL pairs with one or more interactions were detected in the three populations, explaining the wide phenotypic variance ranging from 2.32% to 36.31% and from 1.04% to 2.05% respectively. Among these QTLs, nine QTLs affecting two or more traits were detected on chromosomes 1, 3, 6, 8, 11, and 12 respectively. Thirteen QTLs affecting yield-related traits were detected by nested association mapping (NAM) mapping; four out of thirteen were overlapped with QTLs detected in single mapping population. The additive-dominance QTL affecting yield traits played an important role than that of epistatic QTL. Overall, this research lays a good foundation for the mining of yield-related genes from overwintering cultivated rice and their breeding innovation and utilization.