基于高密度遗传图谱的水稻卷叶QTL定位

QTL Mapping for Rolled Leaf Trait Based on a High-Density Genetic Map in Rice

水稻叶片适度卷曲能提高光能利用率,增加产量。本研究以0738-28-1B (生育中后期叶片卷曲)和岗46B (叶片平展)为亲本构建大小为139个单株的F2作图群体,利用ddRADseq技术得到32 960个高质量多态性SNP、Indel标记,构建了包含1 196个bin标记的高密度遗传图谱,相邻bin之间的平均距离为1.12 cM。结合亲本和群体剑叶卷曲度表型数据,对卷叶性状进行QTL定位,检测到2个QTL位点。qRL-3定位在第3染色体8.24～10.13 Mb区间上,表型贡献率为9.76%;qRL-9定位在第9染色体19.69～19.84 Mb区间上,表型贡献率为25.40%,被认为是控制叶片内卷的主效位点,增效位点均来自亲本0738-28-1B。本研究结果为主效QTL位点的进一步精细定位提供了依据,同时为理想株型育种和超高产育种提供了新的卷叶基因资源。

The moderate leaf rolling index can improve the utilization rate of light energy and increase the yield in rice. In this study, a F2 mapping population including 139 individuals was developed from the cross of two rice lines, 0738-28-1 B and Gang46 B. By using the approach of ddRADseq, 32 960 high quality polymorphic SNP or Indel markers were detected, and a high-density genetic map with 1 196 bin markers was constructed. The average distance between adjacent bin was 1.12 cM. Combined with phenotypic data of the flag leaf rolling index of parents and population, QTLs for rolled leaf trait were identified and 2 QTLs were detected. qRL-3 was located in the region of 8.24-10.13 Mb on chromosome 3 and explained 9.76% of phenotypic variance, qRL-9 as a major QTL was located in the region of 19.69-19.84 Mb on chromosome 9 and explained 25.40% of phenotypic variance, and the effect-increasing loci were both originated from 0738-28-1 B. The study provides a good basis for fine mapping of major QTL qRL-9, and it can be used as a new rolled leaf gene resources in ideal plant type and superhigh yield breeding.