利用重测序的水稻染色体片段代换系群体定位剑叶形态QTL

Mapping of QTLs for Flag Leaf Shape Using Whole-Genome Re-sequenced Chromosome Segment Substitution Lines in Rice

剑叶形态性状(剑叶长、剑叶宽和剑叶面积)是水稻理想株型育种的重要目标性状之一。发掘新的控制水稻剑叶形态性状的基因资源,准确鉴定和定位水稻剑叶形态性状QTL,对开展水稻剑叶形态性状分子生物学研究和理想株型分子育种都具有重要意义。以通过高通量测序而准确获知代换片段位置及长度的一套用籼稻品种9311为受体、粳稻品种日本晴为供体构建的,包括128个染色体片段代换系群体为材料,对剑叶形态性状及其与主穗颖花之间的相关性进行分析,结果表明剑叶面积与剑叶长、宽呈极显著正相关,主穗颖花数与剑叶长、剑叶面积呈极显著正相关。利用多元回归分析方法,结合Bin-map,共鉴定出与水稻剑叶长、宽和面积相关的QTL分别为4、4和6个,贡献率介于4.08%～60.40%。上述QTL的准确定位,为进一步精细定位及克隆相应QTL以及开展水稻剑叶形态性状分子育种奠定了基础。

Flag leaf shape is one of the most important target traits in rice ideal plant type breeding. Identification and localization of new rice flag leaf shape QTLs would be of great significance to facilitate the genetic analysis of complex traits, and provide QTLs/genes to develop new plant type rice varieties via marker-assisted selection. One hundred and twenty eight chromosome segment substitution lines with 9311 as recipient and Nipponbare as donor were genotyped by whole genome resequencing. The pairwise correlation analysis on three flag leaf shape traits was conducted. The correlations Between flag leaf length and flag leaf area, and between flag leaf width and flag leaf area were significantly positive. Correlation analysis revealed that the flag leaf length and flag leaf area have a direct positive impact on spikelet number per panicle. By combining the sequencing-based Bin-map with multiple linear regression analysis, four, four and six QTLs for flag leaf length, flag leaf width and flag leaf area were mapped, respectively, with contributions from 4.08% to 60.40%. The results provided a foundation for fine mapping and subsequent cloning of the QTLs.