QTL Analysis of Fatty Acids Contents in Soybean

Soybean, Glycine max (L.) Merr., is one of the main plant oil sources. Most researches have focused on the improvement of oil content. However, improving fatty acid composition is the main aspect of soybean breeding now. This study aimed at mapping QTLs conferring fatty acids contents in soybean on the genetic map which had been constructed in our laboratory to provide a reference of soybean oil quality breeding. Five kinds of fatty acid contents of 154 F14 and F15 lines devised from a cross of Charleston (♀) × Dongnong 594 (♂) were measured by GC at three locations in two years. The QTLs of fatty acids contents were analyzed with method of composite interval mapping (CIM) by Win QTL Cartographer 2.5. In total, 47 related QTLs distributed on the 13 linkage groups were obtained. Fifteen QTLs were detected in different years or different sites, including two for palmitic acid content, i.e. qPal-C2-2 and qPal-A1-1; four for stearic acid content, i.e. qSt-B1-1, qSt-B1-2, qSt-D1a-1, and qSt-C2-1; three for related with oleic acid content, i.e. qOle-B2-1, qOle-G-1, and qOle-H-1; two for related with linoleic acid content, i.e. qLin-C2-1 and qLin-H-1, and four for linolenic acid content, i.e. qLino-B1-1, qLino-C2-1, qLino-D1b-1, and qLino-J-1. These stable QTLs pave the way for specific fatty acid contents breeding by marker-assisted selection. The number of main-effect QTLs with large effect conferring the contents of fatty acids appeared not as many as expected, it may also subject to a number of the micro-effect genes which failed to detect.