Ueda Yoshiaki, Kondo Katsuhiko, Saito Hiroki, Pariasca-Tanaka Juan, Takanashi Hideki, Ranaivo Harisoa Nicole, Rakotondramanana Mbolatantely, Wissuwa Matthias
Crop, Livestock and Environment Division, Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki Japan.
Present Address: Research Institute of Rice Production and Technology Co., Ltd., Toyoake, Aichi Japan.
Mol Breed. 2024 Sep 2;44(9):57. doi: 10.1007/s11032-024-01494-5. eCollection 2024 Sep.
The rice panicle is the principal organ to influence productivity and traits affecting panicle architecture determine sink size and yield potential. Improving panicle architecture may be effective in increasing yield under low-input conditions, but which traits are of importance under such conditions and how they are genetically controlled is not well understood. Using recombinant inbred lines (RILs) derived from a cross between a modern variety IR64 and a low fertility tolerant accession DJ123, quantitative trait locus (QTL) mapping was conducted under high soil fertility in Japan and low fertility in Madagascar. Among QTL for panicle length (PL) detected, the DJ123 allele increased rachis length at and , while the IR64 allele increased primary branch length at . DJ123 further contributed two QTL for grain width whereas IR64 contributed two grain length QTL. Analysis of lines carrying different combinations of detected QTL indicates that rachis and primary branch lengths are independently regulated, explaining strong transgressive segregation for PL. The positive effects of PL-related QTL were further confirmed by a genome-wide analysis of allelic states in two breeding lines that had been selected repeatedly for total panicle weight per plant under low input conditions. This study provides the genetic basis for complex panicle architecture in rice and will aid in designing an ideal panicle architecture that leads to increased yield under low fertility conditions.
The online version contains supplementary material available at 10.1007/s11032-024-01494-5.
水稻穗是影响产量的主要器官，影响穗部形态的性状决定了库容量和产量潜力。在低投入条件下改善穗部形态可能有效提高产量，但在此类条件下哪些性状重要以及它们如何受到遗传控制尚不清楚。利用现代品种IR64与耐低育性材料DJ123杂交衍生的重组自交系（RIL），在日本高土壤肥力和马达加斯加低肥力条件下进行了数量性状位点（QTL）定位。在检测到的穗长（PL）QTL中，DJ123等位基因在[具体位置1]和[具体位置2]增加了穗轴长度，而IR64等位基因在[具体位置3]增加了一次枝梗长度。DJ123还贡献了两个粒宽QTL，而IR64贡献了两个粒长QTL。对携带不同检测到的QTL组合的株系分析表明，穗轴和一次枝梗长度是独立调控的，这解释了PL强烈的超亲分离现象。通过对在低投入条件下针对单株总穗重反复选择的两个育种系中等位基因状态的全基因组分析，进一步证实了与PL相关QTL的积极效应。本研究为水稻复杂的穗部形态提供了遗传基础，并将有助于设计出在低肥力条件下能提高产量的理想穗部形态。
在线版本包含可在10.1007/s11032-024-01494-5获取的补充材料。
