Primary mapping of QTL for growth-related traits in grass carp (Ctenopharyngodon idellus)

• Published in: Aquaculture international 2020-12, Vol.28 (6), p.2275-2285
• Main Authors: Yu, Chengchen, Xu, Xiaoyan, Li, Jiale, Shen, Yubang
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Freshwater & Marine Ecology; Life Sciences; Zoology
• ISSN: 0967-6120; 1573-143X
• DOI: 10.1007/s10499-020-00594-1

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.