Data_Sheet_1_Major QTLs, qARO1 and qARO9, Additively Regulate Adaxial Leaf Rolling in Rice.docx

Moderate leaf rolling is considered optimal for the ideal plant type in rice (Oryza sativa L.), as it improves photosynthetic efficiency and, consequently, grain yield. Determining the genetic basis of leaf rolling via the identification of quantitative trait loci (QTLs) could facilitate the development of high-yielding varieties. In this study, we identified three stable rice QTLs, qARO1, qARO5, and qARO9, which control adaxial leaf rolling in a recombinant inbred line (RIL) population derived from a cross between Tong 88-7 (T887) and Milyang 23 (M23), using high-density SNP markers. These QTLs controlled the rolling phenotype of both the flag leaf (FL) and secondary leaf (SL), and different allelic combinations of these QTLs led to a wide variation in the degree of leaf rolling. Additive gene actions of qARO1 and qARO9 on leaf rolling were observed in a backcross population. In addition, qARO1 (markers: 01id4854718 and 01asp4916781) and qARO9 (markers: 09id19650402 and 09id19740436) were successfully fine-mapped to approximately 60- and 90-kb intervals on chromosomes 1 and 9, respectively. Histological analysis of near-isogenic lines (NILs) revealed that qARO1 influences leaf thickness across the small vein, and qARO9 affects leaf thickness in the entire leaf and bulliform cell area, thus leading to adaxial leaf rolling. The results of this study advance our understanding of the genetic and molecular bases of adaxial leaf rolling, and this information can be used for the development of rice varieties with the ideal plant type.

适度卷叶被认为是水稻（Oryza sativa L.）理想株型的最优性状，因其可提升光合效率，进而提高籽粒产量。通过鉴定数量性状位点（QTLs）解析卷叶的遗传基础，有助于培育高产水稻品种。本研究利用高密度单核苷酸多态性（Single Nucleotide Polymorphism，SNP）标记，在以通88-7（T887）与密阳23（M23）杂交构建的重组自交系（RIL）群体中，鉴定到3个调控水稻近轴面卷叶的稳定QTL：qARO1、qARO5和qARO9。这些QTL可同时调控剑叶（FL）与倒二叶（SL）的卷叶表型，且不同等位基因组合可使卷叶程度产生广泛变异。在回交群体中，我们观测到qARO1与qARO9对卷叶性状存在加性遗传效应。此外，通过标记01id4854718与01asp4916781定位的qARO1，以及通过标记09id19650402与09id19740436定位的qARO9，已分别被精细定位至第1号染色体和第9号染色体上约60kb和90kb的基因组区间内。对近等基因系（NILs）的组织学分析显示，qARO1可影响小叶脉处的叶片厚度，而qARO9则可调控全叶厚度与泡状细胞面积，进而引发近轴面卷叶。本研究结果加深了我们对水稻近轴面卷叶遗传与分子基础的认知，相关信息可用于培育具备理想株型的水稻品种。