Breeding method of densovirus-resistant silkworms

The invention discloses a breeding method of densovirus-resistant silkworms. The method comprises the following steps of an F1 generation, namely determining a Bmnsd-Z target point, constructing sgRNA-containing plasmid pXL [IE1-DsRed-U6-sgRNA], and leading the sgRNA-containing plasmid pXL [IE1-DsRed-U6-sgRNA] into silkworm bodies; an F2 generation, namely selfing the F1 generation with the plasmid, and screening red fluorescent individuals to obtain F2 generation positive individuals; an F3 generation, namely hybridizing the F2 generation with silkworms expressing a Cas9 protein strain to obtain a bifluorescence offspring, and determining F3 generation positive individuals by performing primary screening on the disease resistance of the densovirus disease and genome identification; an F4generation, namely carrying out F3 generation selfing to screen fluorescence-free individuals, carrying out genome and disease resistance identification again, and determining a fluorescence-free target strain with densovirus