Genetic Resources Center, NARO

Silkworm Genetic Resource Conservation Team

Silkworm genetic resources conservation team is conserving more than 540 races of genetic resources. They are categorized into three groups, native races, bred races and mutants. Native races are those used for silk production in Japan, China, Europe and South-east Asia and respectively and improved more than 90 years ago in each places. Improved races are those bred as parent strains for F1 hybrid production and used for silk production since 1900s. The third group, mutants with various interesting features, is collected for genetic studies. Each of races is reared once a year in spring, summer or autumn, and kept until the next year as diapause eggs. The diapause eggs are maintained at natural condition in summer ,gradually chilled to 5°C in early winter. In the mid winter the eggs are maintained at 2.5~-2.5°C. Just before the starting of annual rearing, the eggs are incubated at 25°C for hatching. Rearing of the silkworms require two months. Simultaneous rearing of many races (~200 races) need special technique and careful handling to prevent contamination of the races. We are studying labor saving and safety method to conserve silkworm genetic resources.

Team Leader


Research Topic : Study of Silkworm Genetic Resources

Team Members

Research Topic
Masatoshi NAKAMURA Senior Principal Researcher Study of Freeze Conservation of Silkworm eggs
Seiji IZUMI Staff Management of silkworms and mulberry
Hajime KOBAYASHI Staff Management of silkworms and mulberry