Growth-related traits are economically important in aquaculture, and their variation is linked to quantitative loci (QTLs). For exploring genetic basis of genetic breeding and improvement of grass carp (Ctenopharyngodon idellus), QTL mapping for growth-related traits was performed with an F2 family of grass carp from the Yangtze River system, including 360 offspring. In this study, we mapped QTLs for body weight, body length, body height, and body width using 99 previously published microsatellite loci. A total of 15 growth-related QTLs were found in 7 linkage groups (LG1, LG2, LG14, LG15, LG16, LG18, and LG21). Four QTLs were related to body weight (qBWH1, qBWH14, qBWH15, and qBWH16), and explained 3.1 to 7.7% of the phenotypic variance. Six QTLs were related to body length (qBL1, qBL2, qBL14, qBL15, qBL16, and qBL18), and these QTLs explained 2.8 to 8.9% of the phenotypic variance. Three QTLs affecting body height (qBH14, qBH15, and qBH16) explained 3.2 to 9.2% of the phenotypic variance. Two QTLs affecting body width (qBW15 and qBW21) accounted for 9.2% and 3.3% of the phenotypic variance, respectively. In order to fine map the QTL affecting body weight on LG1 (qBWH1), 14 additional novel microsatellites were included, and the qBWH1 was relocated with a narrower flanking marker interval of 7.5 cM. This is the first study of QTL mapping in grass carp and provides new insights for the application of molecular marker–assisted breeding in this species.

与生长相关的性状在水产养殖中具有重要的经济意义，其变异与数量位点（QTL）相关。为探索遗传育种和草鱼的改进遗传基础（草鱼），使用来自长江流域（包括360个后代）的F2族草鱼对生长相关性状进行QTL定位。在这项研究中，我们使用99个先前发布的微卫星基因座对体重，体长，体高和体宽的QTL作图。在七个连锁群（LG1，LG2，LG14，LG15，LG16，LG18和LG21）中发现了总共15个与生长相关的QTL。四个QTL与体重有关（qBWH1，qBWH14，qBWH15和qBWH16），并解释了3.1至7.7％的表型变异。六个QTL与体长有关（qBL1，qBL2，qBL14，qBL15，qBL16和qBL18），这些QTL解释了表型变异的2.8％至8.9％。影响身体高度的三个QTL（qBH14，qBH15和qBH16）解释了表型变异的3.2％至9.2％。影响身体宽度的两个QTL（qBW15和qBW21）占9.2％和3。表型差异的3％。为了在LG1（qBWH1）上精确定位影响体重的QTL，还包括14个新的微卫星，并以7.5 cM的较窄侧翼标记间隔重新定位了qBWH1。这是草鱼QTL定位的第一个研究，为在该物种中应用分子标记辅助育种提供了新的见识。