Thousand grain weight (TGW) is one of the three crucial determinants of wheat (Triticum aestivum) grain yield. The identification of functional genes and development of closely linked markers are urgently needed for wheat yield improvements. In this study, quantitative trait locus (QTL) mapping for TGW was carried out using one RIL population in four environments. A total of 8 QTL controlling TGW were detected across four chromosomes. Of them, QGW4B.4-17 was confirmed as a major and stable QTL for TGW increases of 2.19–3.06 g and high PVE of 22.5–36.3% in three environments. It was located in an interval (Rht1-TaGW-4B) of 2 Mb in physical distance that contains the Rht1 locus. Three high-confidence (HC) genes were predicted as potential candidates according to their annotated functions and expression profiles. Furthermore, a cleaved amplified polymorphic sequence (CAPS) marker, TaGW-4B, was developed and verified in a panel of 205 wheat cultivars and showed a highly significant correlation with TGW, demonstrating high value for efficient marker-assisted selection. The study provided a basis for cloning the functional genes underlying the QTL and a practical and accurate marker for molecular breeding.

千粒重（TGW）是小麦（Triticum aestivum）谷物产量的三个关键决定因素之一。迫切需要鉴定功能基因并开发紧密相连的标记，以提高小麦的产量。在这项研究中，TGW的定量性状基因座（QTL）定位是在四个环境中使用一个RIL种群进行的。在四个染色体上共检测到8个QTL控制TGW。其中，QGW4B.4-17被确认为在三个环境中TGW增加2.19–3.06 g和PVE较高的22.5–36.3％的主要且稳定的QTL。它位于包含Rht1的物理距离为2 Mb的间隔（Rht1 - TaGW-4B）中轨迹。根据其注释功能和表达谱，预测了三种高信度（HC）基因作为潜在候选基因。此外，在205个小麦品种中开发并验证了裂解的扩增多态序列（CAPS）标记TaGW-4B，并显示与TGW高度相关，证明了有效的标记辅助选择具有很高的价值。该研究为克隆QTL的功能基因提供了基础，并且为分子育种提供了实用而准确的标记。