Egg color ratio change in a new genetic method developed for improving the mulberry silkworm ( Bombyx Mori L.) balanced with embryonic z-lethality

The mulberry silkworm Bombyx mori L. is a rare insect that has been domesticated it for 5000 years and used to satisfy its needs. The Mulberry silkworm is one of the most convenient species for scientific research in terms of its structure, rearing, and rapid reproduction. In our study, the egg stage sex-linked balanced with embryonic Z-lethal (SLBL), the rare C-8ngl (NGL - new genetic line) breed of the mulberry silkworm Bombyx Mori L., was improved gradually with genetically simple strains with high technological traits. The balance of ℓ1 and ℓ2 embryonic non-allelic lethality linked with the Z chromosome in the F 1 , F 2 , and F 3 generations was analyzed, and the extent to which they were in balance in each generation was determined. The female-to-male ratio in each generation was strictly checked at the egg stage. In the F 1 , F 2 , F 3 , and F 4 generations obtained from backcross breeding, genetic schemes have been developed that show the degree to which embryonic lethal ℓ1 and ℓ2 linked to the Z chromosome are expressed in each generation. Using this genetic method, the balance of embryonic non-allelic genes was achieved in the selection line by the F 4 generation, and as a result, a new line was obtained.