Li Juan, Yang Hongxia, Xu Guangyi, Deng Keli, Yu Jinjin, Xiang Siqian, Zhou Kai, Zhang Qiuli, Li Ruxiang, Li Miaomiao, Ling Yinghua, Yang Zhenglin, He Guanghua, Zhao Fangming
Rice Research Institute, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China.
Rice (N Y). 2022 May 9;15(1):25. doi: 10.1186/s12284-022-00571-7.
Most agronomic traits of rice (Oryza sativa), such as grain length, are complex traits controlled by multiple genes. Chromosome segment substitution lines (CSSLs) are ideal materials for dissecting these complex traits. We developed the novel rice CSSL 'Z414', which has short, wide grains, from progeny of the recipient parent 'Xihui 18' (an indica restorer line) and the donor parent 'Huhan 3' (a japonica cultivar). Z414 contains four substitution segments with an average length of 3.04 Mb. Z414 displays seven traits that significantly differ from those of Xihui 18, including differences in grain length, width, and weight; degree of chalkiness; and brown rice rate. We identified seven quantitative trait loci (QTL) that are responsible for these differences in an F population from a cross between Xihui 18 and Z414. Among these, six QTL (qPL3, qGW5, qGL11, qRLW5, qRLW11, and qGWT5) were detected in newly developed single-segment substitution lines (SSSLs) S1-S6. In addition, four QTL (qGL3, qGL5, qCD3, and qCD5) were detected in S1 and S5. Analysis of these SSSLs attributed the short, wide grain trait of Z414 to qGL11, qGL3, qGL5, and qGW5. Substitution mapping delimited qGL11 within an 810-kb interval on chromosome 11. Sequencing, real time quantitative PCR, and cell morphology analysis revealed that qGL11 might be a novel QTL encoding the cyclin CycT1;3. Finally, pyramiding qGL3 (a = 0.43) and qGL11 (a = - 0.37) led to shorter grains in the dual-segment substitution line D2 and revealed that qGL11 is epistatic to qGL3. In addition, S1 and D2 exhibited different grain sizes and less chalkiness than Z414. In conclusion, the short grain phenotype of the CSSL Z414 is controlled by qGL11, qGL3, and qGL5. qGL11 might be a novel QTL encoding CycT1;3, whose specific role in regulating grain length was previously unknown, and qGL11 is epistatic to qGL3. S1 and D2 could potentially be used in hybrid rice breeding.
水稻（Oryza sativa）的大多数农艺性状，如粒长，都是由多个基因控制的复杂性状。染色体片段代换系（CSSLs）是剖析这些复杂性状的理想材料。我们从受体亲本“西恢18”（一个籼稻恢复系）和供体亲本“湖汉3”（一个粳稻品种）的后代中培育出了新型水稻CSSL“Z414”，其籽粒短而宽。Z414包含四个代换片段，平均长度为3.04 Mb。Z414表现出七个与西恢18显著不同的性状，包括粒长、粒宽和粒重的差异；垩白度；以及糙米率。我们在西恢18和Z414杂交的F群体中鉴定出了七个负责这些差异的数量性状位点（QTL）。其中，在新培育的单片段代换系（SSSLs）S1 - S6中检测到六个QTL（qPL3、qGW5、qGL11、qRLW5、qRLW11和qGWT5）。此外，在S1和S5中检测到四个QTL（qGL3、qGL5、qCD3和qCD5）。对这些SSSLs的分析将Z414短而宽的籽粒性状归因于qGL11、qGL3、qGL5和qGW5。代换定位将qGL11限定在第11号染色体上一个810 kb的区间内。测序、实时定量PCR和细胞形态分析表明，qGL11可能是一个编码细胞周期蛋白CycT1;3的新QTL。最后，将qGL3（a = 0.43）和qGL11（a = - 0.37）聚合到双片段代换系D2中导致籽粒更短，并表明qGL11对qGL3具有上位性。此外，S1和D2的籽粒大小与Z414不同，垩白度也比Z414低。总之，CSSL Z414的短粒表型受qGL11、qGL3和qGL5控制。qGL11可能是一个编码CycT1;3的新QTL，其在调节粒长方面的具体作用此前未知，且qGL11对qGL3具有上位性。S1和D2有可能用于杂交水稻育种。
