Breeding For Cytoplasmic Male Sterile Lines And Restorer Lines With High Oleic Acid Through Molecular Marker-assisted Selection In Brassica Napus L.

Oilseed rape?Brassica napus L.?is one of the most important oil crops in the world.As a monounsaturated fatty acid,High C18:1 rapeseed oil has ideal edible quality,nutritional value,storage and industrial value,playing an extremely important role in food and medical industry.Increasing oleic acid content has been one of the important goals in oilseed rape breeding.In this study,we used J-3111 with high oleic acid content as donor parent,and 621R,L-135R,616A and 195-14A which are pol CMS restorers or sterile lines as the receptors,with the strategy of traditional backcross breeding combined with molecular marker-assisted selection?MAS?,to obtain the pol CMS restorer lines and sterile lines with high oleic acid content and high genetic background recovery rate comparing to the receptors,respectively.The main results are as follows:1.The populations of BC₁F₁,BC₂F₁,BC₃F₁,BC₃F₂,BC₃F₃,BC₄F₁ and BC₄F₂between the donor J-3111 and four receptors 621R,L-135R,616A and 195-14A were established in order respectively.With the help of foreground and background selection,22 and 19 individuals with high oleic acid and fertility genotype?RfpRfpBnaA.fad2.aBnaA.fad2.a??restorer?,and 30 and 19 individuals with high oleic acid and sterility genotype?rfprfpBnaA.fad2.aBnaA.fad2.a??male sterile line?were obtained in the BC₃F₃ populations derived from the combiantions of 616A×J-3111 and195-14A×J-3111,respectively.And 7 and 24 individuals with the genotype RfpRfpBnaA.fad2.aBnaA.fad2.a?restorer?,and 1 and 18 individuals with the genotype rfprfpBnaA.fad2.aBnaA.fad2.a?male sterile line?were obtained in BC₄F₂ population derived from the same combiantions of 616A×J-3111 and 195-14A×J-3111,respectively.And 1 and 16 individuals with the genotype RfpRfpBnaA.fad2.aBnaA.fad2.a in BC₄F₂ population derived from 621R×J-3111 and L-135R×J-3111 combiantions,respectively.After field phenotype selection and backgrond selection,10 individuals?2fertile and 2 sterile for 616A,2 fertile and 2 sterile for 195-14A,and 2 fertile for L-135R?with high genetic background recovery rate were selected for re-sequencing analysis.And the background recovery rate was 97.93%to 99.45%.The genetic background of these 10plants had nearly no differences with their corresponding recurrent parents,but selected region showed polymorphism.2.The oleic acid content of all 39 selected individuals derived from different combinations were measured by gas chromatography.The results showed that the oleic acid content of the donor?genotype BnaA.fad2.aBnaA.fad2.a?is 76.14%,the receptors?genotype BnaA.FAD2.ABnaA.FAD2.A?is between 61.11%to 65.32%,7 selected heterozygous individuals?genotype BnaA.FAD.ABnaA.fad2.a?is between 67.37%to70.57%,and 32 selected homozygous individuals?genotype BnaA.fad2.aBnaA.fad2.a?is between 68.15%to 75.18%.And significant difference was observed in the oleic acid content between the selected individuals and the receptor parents.3.The main yield-related traits of the 10 selected individuals with the highest genetic background similarity to their receptor parents were evaluated,and no significant differences were detected between the selected and their receptor parents?L-135R,616A and 195-14A?in the traits of silique length,number of seeds per silique and throusand seed weight.