Bian Zhong, Cao Dongping, Zou Yiting, Xie Dong, Zhuang Wenshu, Sun Zixing, Mou Nana, Sun Yangyang, Zhang Changquan, Li Qianfeng, Liu Qiaoquan, Zhang Lin
Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, China.
Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops/Jiangsu Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, China.
Rice (N Y). 2024 Jul 12;17(1):43. doi: 10.1186/s12284-024-00723-x.
Rice is one of the major staples that feeds about one half of the global populations, and it is important to identify the genetic loci for the traits related to yield improvement. Lodging will cause severe yield loss when it happens, and stem diameter has been characterized as an important trait for lodging resistance. However, most QTLs for stem diameter have not been finely dissected due to their sensitivity to environmental fluctuation.
In this study, we performed QTL analysis for stem diameter using populations derived from Nipponbare (NIP) and strong culm variety YYP1, and confirmed the single and combined effect of three major QTLs by recombinant inbred lines (RILs). Based on the QTL location, we found that qWS5 is a novel QTL not well characterized before. To finely dissect the novel locus, several recombinant heterogeneous inbred families (HIFs) were selected from the RILs for linkage analysis and their derived nearly isogenic lines (NILs) were subjected to detailed trait investigation throughout different years. The HIF-NILs strategy confined the QTL to about 380 kb region supported by repeated genotype and phenotype data, and it lays the foundation for QTL cloning in the future. In addition, introgression of the QTL to an elite japonica variety SD785 was performed by successive backcrossing, and it confirmed the value of qWS5 in increasing stem diameter and other agronomic traits during rice breeding.
We prove that qWS5 is a novel QTL with relatively stable effect for stem diameter and the QTL can be finely mapped to small region by the HIF-NILs strategy. The result will facilitate the improvement of rice lodging resistance by molecular marker assisted selection breeding.
水稻是养活全球约一半人口的主要主食之一，确定与产量提高相关性状的基因座很重要。倒伏发生时会导致严重的产量损失，茎粗已被认为是抗倒伏的重要性状。然而，由于茎粗对环境波动敏感，大多数控制茎粗的数量性状基因座（QTL）尚未得到精细剖析。
在本研究中，我们利用日本晴（NIP）和强秆品种YYP1构建的群体对茎粗进行了QTL分析，并通过重组自交系（RIL）证实了三个主要QTL的单一和联合效应。基于QTL定位，我们发现qWS5是一个以前未被充分表征的新QTL。为了精细剖析这个新基因座，从RIL中选择了几个重组异质自交家系（HIF）进行连锁分析，并对其衍生的近等基因系（NIL）在不同年份进行了详细的性状调查。HIF-NIL策略将该QTL定位到约380 kb的区域，这一结果得到了重复的基因型和表型数据的支持，为未来的QTL克隆奠定了基础。此外，通过连续回交将该QTL导入优良粳稻品种SD785，证实了qWS5在水稻育种中增加茎粗和其他农艺性状方面的价值。
我们证明qWS5是一个对茎粗具有相对稳定效应的新QTL，并且可以通过HIF-NILs策略将该QTL精细定位到小区域。该结果将有助于通过分子标记辅助选择育种提高水稻的抗倒伏能力。
