Genetically Modified Silkworm Breeds (Bombyx mori L.) with Sexual Dimorphism at the Initial Stage of Ontogenesis

The purpose of the work was to evaluate the breeds of the world silkworm collection of the Scientific Research Institute of Sericulture (SRIS) labelled by sex at the stage of eggs of silkworm by biological characteristics for their use in hybridization. The eggs of silkworm of these genetically modified breeds can be easily separated by color (by sex) before reaching the imago stage.

The work was carried out in the laboratory of genetics and breeding of the silkworm of the SRIS on the materials of the living collection of the silkworm in 2020-2022.

The search and selection of breeds for hybridization was carried out by the ranking method. The ranking method consists in the ability to establish a relationship between the features, which are expressed by the order of the place occupied by each member in the aggregate, i.e. the place of rank in the variation series.

Hybrids from breeds labeled by sex at the stage of silkworm eggs with 100% purity of preparation, with the maximum manifestation of heterosis in reproductive and biological indicators, differ in: a high number of normal eggs in a clutch of C-12×C-10 - 614pcs, C–5×C-13 - 598pcs, C-12×C-14 – 598 pieces; caterpillar viability – C-12×C-10 – 96,5%, C-5×C-13 – 96,0%, C-12×C-14 – 96,2%; content of raw silk, – C-12×C-10 – 22,2%, C-5×C-13 – 22,0%, C-12×C-14 – 20,3%.

By the methods of traditional breeding selection at all stages of development, improved lines of silkworm breeds C-5, C-10, C-12, C-13, C-14 were bred in terms of reproductive indicators, hatching of silkworm eggs, the viability of caterpillars, weight and content of raw silk of cocoons.