Xu Guangyi, Deng Keli, Yu Jinjin, Li Qiaolong, Li Lu, Xiang Aoni, Ling Yinghua, Zhang Changwei, Zhao Fangming
Rice Research Institute, Academy of Agricultural Science, Engineering Research Center of South Upland Agriculture, Ministry of Education, Southwest University, Chongqing 400715, China.
Int J Mol Sci. 2023 Jul 27;24(15):12013. doi: 10.3390/ijms241512013.
Rice chromosomal segment substitution lines (CSSLs) are ideal materials for studying quantitative traits such as grain size. Here, a rice large-grain CSSL-Z403 was identified among progeny of the recipient Xihui18 and the donor Jinhui35 based on molecular marker-assisted selection. Z403 carried 10 substitution segments with average length of 3.01 Mb. Then, a secondary F population derived from a cross between Xihui18 and Z403 was used to map quantitative trait loci (QTL) for grain size. Six QTLs distributed on chromosomes 5, 6, 7, 9 and 12 were detected. Finally four single-segment substitution lines (SSSLs) and two dual-segment substitution lines (DSSLs) carrying these target QTLs were constructed, and 10 novel QTLs were identified by four SSSLs. The large grain of Z403 was controlled at least by , , and , and its grain weight was influenced through grain length QTL such as , , and , as well as grain width QTL such as , , and . Among 16 QTLs, four QTLs including , etc., might be novel compared with the reported documents. Again, positive or less negative epistatic effects between two non-allelic QTLs (additive effect > 0) may assist screening the genotype with larger grain size in further selection.
水稻染色体片段代换系（CSSLs）是研究粒型等数量性状的理想材料。在此，基于分子标记辅助选择，在受体西恢18和供体金恢35的后代中鉴定出一个水稻大粒CSSL-Z403。Z403携带10个代换片段，平均长度为3.01 Mb。然后，以西恢18和Z403杂交产生的次级F群体用于定位粒型数量性状基因座（QTL）。检测到分布在第5、6、7、9和12号染色体上的6个QTL。最后构建了携带这些目标QTL的4个单片段代换系（SSSLs）和2个双片段代换系（DSSLs），并通过4个SSSLs鉴定出10个新的QTL。Z403的大粒至少受 、 、 和 控制，其粒重受粒长QTL如 和 以及粒宽QTL如 、 和 的影响。在16个QTL中，包括 等在内的4个QTL与已报道文献相比可能是新的。此外，两个非等位QTL之间的正向或较小负向上位性效应（加性效应>0）可能有助于在进一步选择中筛选出粒型较大的基因型。
