利用QTL-Seq结合分子标记定位粳稻垩白粒率控制位点qChalk8

Mapping of qChalk8 Controlling Chalky Rice Rate in japonica Rice by Combining QTL-Seq with Molecular Markers

[目的]垩白是影响稻米外观品质的重要性状。本研究旨在利用QTL-Seq和分子标记作图定位粳稻垩白粒率调控相关的QTL。[方法]利用高垩白粒率粳稻材料拉木加和低垩白粒率粳稻品种水晶3号构建F_(2)分离群体,将两份独立的F_(2)群体分别种植于河南原阳和海南三亚,两个群体单株垩白粒率考种后分别选取极端个体混池进行QTL-Seq分析,然后使用分子标记作图对稳定的QTL进行验证。[结果]两个F_(2)群体的QTL-Seq分析发现8号染色体存在一个较为稳定的QTL位点qChalk8。进一步通过分子标记作图将该QTL定位于17.6-18.5Mb,该QTL位点的LOD值为7.08,表型贡献率为15.9%。[结论]利用QTL-Seq和分子标记作图定位了粳稻垩白粒率相关QTL-qChalk8,为粳稻垩白调控基因进一步的精细定位和基因克隆奠定了基础。

[Objective]Chalkiness is an important characteristic that affects the appearance quality of rice grains.This study aims to use QTL-Seq and molecular marker mapping methods to locate QTLs related to chalky rice rates in japonica rice.[Method]F_(2) segregating populations were constructed using the japonica germplasm Lamujia with a high chalky rice rate and the japonica variety Shuijing 3 with a low chalky rice rate.Two independent F_(2) populations were planted in Yuanyang,Henan Province,and Sanya,Hainan Province,respectively.The single-plant chalky rice rate was examined,and extreme individuals were pooled for QTL-Seq analysis.Reliable QTLs were then subjected to verification using molecular marker mapping.[Result]QTL-Seq analysis of the two F_(2) populations revealed the existence of a stable chalky rice rate QTL on chromosome 8,designated as qChalk8.Further molecular marker mapping confined the QTL to a genomic region between 17.6 Mb and 18.5 Mb.The LOD score for qChalk8 was 7.08,and qChalk8 could explain 15.9% of the phenotypic variation.[Conclusion]QTL-Seq and molecular marker mapping successfully identified qChalk8 related to chalky rice rates in japonica rice.The localization of qChalk8 establishes a foundation for further fine mapping and gene cloning of the chalkiness regulatory gene in japonica rice.