不同环境基于高密度遗传图谱的稻米外观品质QTL定位

为解析稻米外观品质遗传基础, 挖掘稳定存在的控制稻米外观品质性状的QTL, 本研究以籼稻品种V20B和爪哇稻品种CPSLO17作为亲本, 构建包含150个重组自交家系(recombinantion inbred line, RIL)的RIL作图群体, 进行外观品质性状QTL定位分析。利用特定位点扩增长度测序(SLAF-seq)技术, 构建了一个由12个连锁群包含8602个标记, 平均间距为0.29 cM的高密度遗传图谱。采用IciMapping 4.0软件的ICIM-ADD方法在3种环境(贵阳、贵定、三亚)对4个外观品质性状(粒长、粒宽、垩白度和垩白粒率)进行QTL (quantitative trait locus)定位分析。结果表明: 3种环境共检测到9个粒长QTL、6个粒宽QTL、3个垩白度QTL和4个垩白粒率QTL; 有5个QTL在多个环境被重复检测到, 其中3种环境都定位到的粒宽QTL qGW5-1和垩白度QTL qCha5-1为同一定位区间(第5染色体的Marker1642127-Marker1514505); 此外, 垩白度QTL qCha5-2的定位区间(Marker1554573-Marker1554589)和垩白粒率QTL qCGP5-2也是一样的。序列比对发现QTL qCha5-1定位区间仅51.5 kb, 是新的垩白性状主效QTL。本研究结果不仅为挖掘新的外观品质性状基因奠定基础, 也有助于开发新的分子标记进行水稻外观品质性状遗传改良。

QTL Mapping for Rice Appearance Quality Traits Based on a High-density Genetic Map in Different Environments

To analyze the genetic basis of appearance quality of rice, explore QTL which controlled rice appearance quality related traits stably existing, a mapping population of 150 lines (recombination inbred lines, RIL), derived from a cross between rice varieties V20B and CPSLO17, was applied to analysis QTL location of appearance quality trait. The specific locus amplified fragment sequencing (SLAF-seq) technology was employed to construct a high-density genetic map in rice (Oryza sativa L.). A genetic map included 8602 markers on the 12 linkage groups was successfully constructed, which with an average distance of 0.29 cM between adjacent markers. The ICIM-ADD method of IciMapping 4.0 software was used to analyze QTL location for four appearance quality traits, including grain length (GL), grain width (GW), chalky grain rate, and chalkiness degree in three environmental conditions (Guiyang, Guiding, and Sanya). A total of nine QTLs for grain length (GL), six QTLs for grain width (GW), four QTLs for chalkiness size, three QTLs for chalkiness degree traits were detested in three environments. Five QTLs were repeatedly detected in multiple environments, of which the QTL qGW5-1 and qCha5-1 with the same localization interval (Marker1642127-Marker1514505 on chromosome 5) were repeatedly located in all three environments. In addition, the positioning interval of chalkiness QTL qCha5-2 (Marker1554573-Marker1554589) is the same as the chalkiness size QTL qCGP5-2. The sequence alignment found that the location interval of QTL qCha5-1 was only 51.5 kb, which was a new main effect QTL for chalkiness trait. These results lay the foundation for further exploiting candidate gene of appearance quality, which also contribute to the development of new molecular markers for rice appearance quality traits genetic improvement.