Deng Xiaoxiao, Kong Weilong, Sun Tong, Zhang Chenhao, Zhong Hua, Zhao Gangqing, Liu Xuhui, Qiang Yalin, Li Yangsheng
State Key Laboratory of Hybrid Rice, Key Laboratory for Research and Utilization of Heterosis in Indica Rice, Ministry of Agriculture, College of Life Sciences, Wuhan Univ., Wuhan, 430072, China.
Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China.
Plant Genome. 2022 Mar;15(1):e20171. doi: 10.1002/tpg2.20171. Epub 2021 Nov 22.
Exploitation of heterosis between indica and japonica has important significance in scientific research and agriculture application. However, the molecular mechanism of grain shape heterosis in indica-japonica hybrid remains unknown in rice (Oryza sativa L.). To reveal the genetic mechanism of grain shape in indica--japonica hybrid, we constructed a high-generation recombinant inbred line (RIL) population and two testcross hybrid populations derived from the cross of RILs and two cytoplasmic male sterile material (YTA and Z7A) and then performed a bin mapping-based quantitative trait locus (QTL) mapping of multiple grain shape traits, such as grain length (GL), grain width (GW), and grain length-to-width ratio (GLWR). A total of sixteen QTLs and 30 heterosis-related QTLs of grain shape traits were detected. We found that GS3, GS5, and OsPPKL2 were also correlated with grain shape both in RILs and two testcross hybrid populations. Homologous gene analysis emphasized two candidate grain shape-associated genes (LOC_Os06g14260 and LOC_Os04g51950). Our findings uncover multiple grain shape heterosis-related loci and provides a new insight into heterosis mechanism of grain shape in rice.
籼粳亚种间杂种优势的利用在科学研究和农业应用中具有重要意义。然而，水稻（Oryza sativa L.）中籼粳杂交种粒形杂种优势的分子机制尚不清楚。为揭示籼粳杂交种粒形的遗传机制，我们构建了一个高世代重组自交系（RIL）群体以及两个由RIL与两个细胞质雄性不育材料（YTA和Z7A）杂交衍生的测交杂种群体，然后对多个粒形性状，如粒长（GL）、粒宽（GW）和长宽比（GLWR）进行基于区间作图的数量性状位点（QTL）定位。共检测到16个粒形性状的QTL和30个与杂种优势相关的QTL。我们发现GS3、GS5和OsPPKL2在RIL群体和两个测交杂种群体中均与粒形相关。同源基因分析确定了两个候选粒形相关基因（LOC_Os06g14260和LOC_Os04g51950）。我们的研究结果揭示了多个与粒形杂种优势相关的位点，并为水稻粒形杂种优势机制提供了新的见解。
