The invention belongs to the technical field of rape
molecular breeding, in particular relates to a preparation method of a codominant SNP (
Single Nucleotide Polymorphism)
molecular marker closely linked with the
linolenic acid content of a cabbage type rape and application thereof as the marker in the auxiliary selection of the low
linolenic acid cabbage type rape. The low
linolenic acid cabbage type rape strain A254 and high linolenic acid cabbage type rape strain A177 genomes
DNA are amplified by using primers to respectively obtain two
DNA amplified fragments, then
cloning, sequencing and
nucleotide sequences comparison are carried out on the four
DNA amplified fragments; according to the difference of the sequences, the second bases at 3'-end of a
forward primer and a
reverse primer are mispaired, primer pairs of YQ-fad31-1, YQ-fad31-2, YQ-fad32-1 and YQ-fad32-2 are designed, the PCR (
Polymerase Chain Reaction) amplification is carried out on the primer pairs of YQ-fad31-1, YQ-fad31-2, YQ-fad32-1 and YQ-fad32-2, and the PCR amplification and
group detection effects are analyzed to obtain the codominant SNP
molecular marker linked with low linolenic acid genes of the cabbage type rape. The invention provides a new marker for the rape
molecular breeding. In the invention, a mispairing strategy of the 3'-end of the primer is firstly applied to the development and the detection of the SNP polymorphic marker of the cabbage type rape, and a means of synchronously mispairing the
forward primer and the
reverse primer is firstly adopted to develop the SNP marker based on the PCR amplification and an
agarose gel electrophoresis in the cabbage type rape of an allopolyploid
crop. The invention synchronously discloses a method for preparing the
molecular marker and the application thereof.