Molecular Systematic Studies on Chinese Mandarina Silkworm (Bombyx mandarina M.) and Domestic Silkworm (Bombyx mori L.)

Molecular systematic studies on mandarina silkworm (Bombyx mandarina M.) in 11 regions in China and 25 representative strains of domestic silkworm (Bombyx mori L.) were conducted using molecular biology techniques. Results obtained from the analysis of DNA polymorphism and clustering of all the silkworm samples provide new evidence for the view that the domestic silkworm originated from the Chinese mandarina silkworm. On the basis of literature reviewing, a new hypothesis on the origin of the domestic silkworm was put forward. It was thought that the domestic silkworm was most probably domesticated from the Chinese mandarina silkworm of different ecotypes including monovoltinism, bivoltinism and multivoltinism; and that the domestic silkworm had the genetic background of monovoltinism, bivoltinism and multivoltinism at the very beginning of the domestication. The current strains of the domestic silkworm of different voltinism are the evolutionary results of thousands of years of rearing and artificial selections.