Zhao Qiong, Wang Tian, Pei Fa-Jing, Chen Ying, Chang Xiao-Yu, Mi Jia-Ming, Zhang Yuan-Ming
Department of Crop Genetics and Breeding, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, China.
Plant Cell Environ. 2025 Jun;48(6):3890-3901. doi: 10.1111/pce.15397. Epub 2025 Jan 20.
Grain size and weight of main-crop are larger than those of ratoon rice, indicating that increasing grain size and weight of ratoon rice is an effective way to increase rice yield. Thus, grain length (GL), grain width (GW), and thousand-grain weight (TGW) of main-crop and ratoon rice in 159 indica rice accessions were used to associate with 2 017 495 SNP markers to detect quantitative trait nucleotides (QTNs) and their interactions with meteorological factors (QMIs), such as temperature and sunlight hours. Around 59 QMIs identified for temperature and 80 QMIs identified for sunlight hours, first, candidate gene LOC_Os02g40840 for GW and LOC_Os04g45480 for TGW were found to interact with temperature, while LOC_Os01g19970 for GL, LOC_Os02g39360 and LOC_Os07g05720 for GW, and LOC_Os07g49460 for TGW were found to interact with sunlight hours. Based on the results of previous studies, LOC_Os04g45480 exhibits high expression levels in the main-crop under higher temperature, thereby enhancing the accumulation of the auxin receptor TIR1. TIR1, in turn, promotes starch accumulation in the endosperm, explaining why TGW is heavier in main-crop than in ratoon rice. Finally, the analysis of best linear unbiased prediction values revealed 1 (LOC_Os08g10350) and 3 (LOC_Os02g50860, LOC_Os08g28680, and LOC_Os08g29160) candidate genes responsible for GW and TGW, respectively. In addition, we discussed the four available and six unavailable candidate genes in ratoon rice breeding. This study provides new method and genes for studying differences in grain size-related traits between main-crop and ratoon rice.
主季稻的粒长和粒重均大于再生稻，这表明增加再生稻的粒长和粒重是提高水稻产量的有效途径。因此，利用159份籼稻品种的主季稻和再生稻的粒长（GL）、粒宽（GW）和千粒重（TGW）与2017495个单核苷酸多态性（SNP）标记进行关联分析，以检测数量性状核苷酸（QTNs）及其与温度和日照时数等气象因子的相互作用（QMIs）。分别鉴定出约59个与温度相关的QMIs和80个与日照时数相关的QMIs，首先，发现GW的候选基因LOC_Os02g40840和TGW的候选基因LOC_Os04g45480与温度相互作用，而GL的LOC_Os01g19970、GW的LOC_Os02g39360和LOC_Os07g05720以及TGW的LOC_Os07g49460与日照时数相互作用。基于先前的研究结果，LOC_Os04g45480在较高温度下的主季稻中表现出高表达水平，从而增强了生长素受体TIR1的积累。反过来，TIR1促进胚乳中淀粉的积累，这解释了为什么主季稻的TGW比再生稻的更重。最后，最佳线性无偏预测值分析分别揭示了1个（LOC_Os08g10350）和3个（LOC_Os02g50860、LOC_Os08g28680和LOC_Os08g29160）分别负责GW和TGW的候选基因。此外，我们还讨论了再生稻育种中4个可用和6个不可用的候选基因。本研究为研究主季稻和再生稻粒型相关性状差异提供了新方法和基因。
