Molecular module related to content of crassostrea gigas polyunsaturated fatty acid C20: 3 omega6 and application

The invention belongs to the field of genetic engineering and genetic breeding, and relates to a molecular module related to the content of polyunsaturated fatty acid C20: 3 omega6 of crassostrea gigas and application of the molecular module to screening of parent crassostrea gigas. The molecular module is a block 1 or/and a block 2, the block 1 is located on a No.2 chromosome scaffold 814 of a Crassostrea gigas genome, and the size of the block 1 is about 13kb interval range of 134, 468-147, 686 bp; the block 2 is located on a No.1 chromosome scaffold 460 of a pacific oyster genome, and the size of the block 2 is about 18kb interval range of 96, 511-114, 852 bp. By utilizing the method disclosed by the invention, rapid detection of key SNP loci can be realized, so that parent shellfish of dominant genotype combination can be screened through the molecular module, and the method is used for screening the parent shellfish in the genetic improvement process of the content of unsaturated fatty acid C20: 3 omega6