Breeding For Restorer Lines With High Oleic Acid By Molecular Marker-assisted Selection In Brassica Napus L

Rapeseed is one of the largest oil crop in China,and rape oil accounts for about 50%of self-produced edible vegetable oil.As a monounsaturated fatty acid,Oleic acid is an important component of rapeseed oil.High-oleic rape oil has ideal edible quality,nutritional value,storage and industrial value,playing an extremely important role in food,industry and medicine.Therefore,increasing oleic acid content has been one of the important goals in rape quality breeding.In this study,we used J-4008 and L3 with high oleic acid content as donor parents,while restorer lines 6105R,ZY28R,and GCZS11 as the receptors.Combining the strategy of traditional backcross breeding with molecular marker-assisted selection（MAS）,we obtained restorer lines with high oleic content and high genetic background recovery rate comparing to the receptors.The main results are as follows:1.Based on the genome re-sequencing of five rapeseed inbred lines（J-4008,L3,6105R,ZY28 and GCZS11）,the In Del markers（FAD2-J-15,FAD2-J-38 and FAD2-L-2,FAD2-L-9）closely linked to Bna A.FAD2.a were developed.Based on donor parent（L3）Bna A.FAD2.a one SNP mutation,two Bna A.FAD2.A allele-specific SNP markers L3-FAD2a-1 and L3-FAD2A-1 were developed.L3-FAD2a-1 was used for detection of high oleic acid genotypes Bna A.FAD2.a,while L3-FAD2A-1 was used for detection of low oleic acid genotypes Bna A.FAD2.A.Based on the 478bp mutation between the donor parent J-4008 and the recurrent parent,one KASP markers for Bna A.FAD2.a were also designed for foreground selection.2.The BC₁F₁,BC₂F₁,BC₃F₁ and BC₃F₂populations derived from the cross between the donor J-4008 or L3 and three receptors were established in order.Based on foreground and background selection,5,4 and 7 individuals with high oleic acid genotype（Bna A.FAD2.a/Bna A.FAD2.a）were obtained from the BC₃F₂ populations derived from the cross of 6105R×J-4008,ZY28×J-4008 and GCZS11×J-4008,respectively.And 6,3 and 5individuals with high oleic acid genotype（Bna A.FAD2.a/Bna A.FAD2.a）were obtained from the BC₃F₂ populations derived from the cross of 6105R×L3,ZY28×L3 and GCZS11×L3,respectively.3.The oleic acid content of seeds from 24 selected individuals derived from different combinations and 4 parents were measured by gas chromatography.The results showed that the oleic acid content of the donor,the receptors,the selected heterozygous individuals and the homozygous individuals were 76.03%,60.12%-64.58%,64.26%-68.42%and 66.14%-75.34%,respectively.The results showed that the oleic acid content of the selected individuals were significantly higher than that of their recurrent parent.4.The results showed that no significant differences were detected between the improved lines with homozygous genotype of Bna A.FAD2.a and their receptor parents（6105R,ZY28 and GCZS11）in the traits of silique length,number of seeds per silique and thousand seed weight.