Abstract: 【Objective】Rapeseed oil contains many fatty acid components and the major goal in breeding and genetic research is to increase of the oleic acid content and decreases of the linolenic acid and erucic acid content. QTL mapping of oil quality related oleic acid, linolenic acid and erucic acid content in Brassica napus was made by using the high density SNP genetic map which was constructed from the high generation RIL population with the newly developed rapeseed 60K chip array. 【Method】 The high generation RIL population was derived from the cross of high erucic acid female parent GH06 and low erucic acid male parent P174. Seeds harvested from Giessen and Hohenlieth in Germany in 2008 and again in Giessen in 2009 were measured by NIRS with three technical repeats. The RIL population genotype was analyzed with the newly developed rapeseed 60K chip array. The DNA preparation and the chip preparation were processed strictly according to Infinium HD Assay Ultra manual of Illumina Inc. The SNP linkage map was constructed by using MSTmap program with minimum LOD 5.0. The reference SNP genetic map contains 2756 SNP markers, covering 1 832.4 cM of B. napus genome. QTL mapping of oleic acid, linolenic acid and erucic acid content was conducted by composite interval mapping using software Windows QTL Cartographer. 【Result】 Trait analysis indicated that the oleic acid and erucic acid contents were controlled by major genes, and their correlation coefficient was higher than -0.95 in the three different environments at significant level. Linolenic content showed a negative and positive correlation with erucic acid and oleic acid content, respectively. Two major QTL located on A08 and C03 were detected both for oleic acid and erucic acid content at the same position. In the three different environments, the major oleic acid QTL accounted for the phenotype variation from 19% to 31%, and the major erucic acid QTL effects varied from 19% to 34%, and the two major QTL for oleic acid and erucic acid content gave opposite direction of additive effect. The additive effect of the major erucic acid QTL on A08 and C03 come from the low oleic acid and high erucic acid parent GH06 with value varied from 7.6 to 9.6 in three different environments. Different QTL for linolenic acid was found across three different environments with QTL effects varied from 3% to 12%, which was coincided with that the linolenic acid was a typical quantitative trait, and was easily affected by the environment factors. The genetic map and physical map comparison discovered that the FAD2 gene and FAE1 gene located on the QTL qA05C18:3 and qA08C22:1confidence interval, respectively. 【Conclusion】 The oleic acid, linoleic acid and erucic acid content QTL was mapped with a new set of rapeseed 60K chip array, and the major QTL on A08 and C03 for erucic acid content is also responsible for oleic acid content. The mapping results are helpful to the fatty acid composition QTL comparison in different populations based on the same rapeseed 60K chip array.

Key words: Brassica napus , SNP , fatty acid , QTL