Dissection Of Additive, Epistatic And Qtl X Environment Effects Involved In Oil Content Variations In Rapeseed

In this study, we observed variation of rapeseed oil content in SG population across 11 environments. A joint mapping was conducted to detect the quantitative trait loci (QTL) involved in oil content variation. We examined additive main (a), epistatic effects (aa) and their interactions with environments (QE). Apart from a of 12 QTL (collectively to 6.74% of oil content), aa of 18 locus pairs contributed to 5.36% difference, explaining 45.3% of phenotypic variation in the population. Moreover, 28 QE interactions contributed to a change of 1.55% in oil content in each environment, accounting for 13.3% phenotypic variation. Two environmentally sensitive QTL (OilC2 and OilC8-1) exhibited a small a (0.17) but strong ae (0.41 and 0.32 averagely). These two QTL were also frequently involved in epistatic interactions. However, two major QTL (OilA7 and OilC8-2) showed few QE and uninvolved in epistasis. In conclusion, a and aa were the dominant contributors to oil content in rapeseed, while QE accounted for 10-15% of variation. The results suggest OilA7 and OilC8-2 are potential candidates for breeding utilization and gene cloning.