QTL Identification for Fatty Acid Content in Rapeseed ( Brassica napus L.)

Abstract

A segregation population BC 1F 1 of rapeseed ( Brassica napus L.), derived from a cross between a low erucic acid content line APL01 and a high erucic acid content variety M083, was used to construct the genetic map and identify auantitave trait loci (QTLs) linked to main fatty acid composition in rapeseed. The genetic map containing 19 linkage groups was constructed with 251 markers of RAPD, SSR, and SRAP. By means of WinQTLCart scanning, 5 QTLs linked to palmitic acid (C16:0) content were identified, which were located on linkage groups N3, N8, N10, and N13, respectively. The main-effect QTLs qPA8-1 and qPA13 linked to palmatic acid content in rapeseed explained 11.31% and 14.47% of the palmitic acid content variation in the segregation population BC 1F 1, respectively. Three QTLs linked to stearic acid (C18:0) content were identified, which were located on the linkage groups N1, N8, and N16. The main-effect QTL qST16 accounted for 12.22% of phenotypic variation. Two QTLs, qOL8 and qOL13, the main-effect QTLs linked to oleic acid (C18:1) content, were located in the region of m11e37b– A0226Ba267 on linkage group N8 and m18e46– m20e25a on N13. These QTLs accounted for 11.73% and 27.14% of phenotypic variation, respectively. Three QTLs linked to linoleic acid (C18:2) content were identified, and the main-effect QTL qLI8-1 accounted for 13.25% of phenotypic variation. Three QTLs, qLN1, qLN8, and qLN11, linked to linolenic acid (C18:3) content, were identified, but they had small effects on C18:3 and could be regarded as minor-QTLs. Four QTLs were linked to eicosenoic acid (C20:1) content, and three of them, qEI8-1, qEI8-2, and qEI13, were main-effect QTLs, accounting for 12.20%, 10.22%, and 11.14% of phenotypic variation, respectively. Two main-effect QTLs linked to erucic acid (C22:1) content, qER8 and qER13, were located in the region of m11e37b– A0226Ba267 on linkage group N8 and A0301Bb398– m18e46 on N13, accounted for 16.74% and 31.32% of phenotypic variation, respectively. The main-effect QTLs linked to fatty acid content, which were located in the region near marker m11e27b on linkage group N8 and m18e46 on linkage group N13, could be used in marker-assisted selection in fatty acid improvement in rapeseed.