Abstract: In the present study， doubled haploid （DH） population developed from a cross between the German cultivar Sollux and the Chinese line Gaoyou was used. Both parents possessed high glucosinolate content， and large variation within population. The glucosinolate content of 282 DH lines were collected for QTL mapping over four environments. The objectives of this study were to investigate the genetic basis of transgressive segregation observed in the population， and to discover new allele for low\|glucosinolate\|content rapeseed breeding. It was shown that eight QTL with additive effects and eight pairs of loci with additive×additive epistasis were detected， which together accounted for more than 50% of the phenotypic variation. Among them， three（GSLqA9\|1， GSLqC2 and GSLqC9）were probably homozygous to the previously identified major QTLs on A9， C2 and C9， while GSLqA9\|2， GSLqA8 and GSLqC1were more likely to be new identified loci. These favorable alleles were candidate to decrease the seed glucosinolate content to below 15 μmol·g-1， which would improve the feeding value of rapeseed meal. The sum of epistatic effects from eight pairs of loci accounted for half of total additive effects， which might be the reason for the difficulties to further reduce or totally remove the glucosinolate content in rapeseeds. Eight markers linked to the 5 QTL showed good fitness between marker genotypes and trait phenotypes， and were of great potential for the future breeding.

Key words: rapeseed, QTL, glucosinolate, molecular breeding