Study of breeding large Antheraea yamamai for greater silk productivity by backcross

抄録

Backcross of Japanese oak silkmoth Antheraea yamamai (A. yamamai) was undertaken to breed a strain with greater silk production capacity by hybridizing a strain showing a high fertilization rate (SUB-52) and a strain showing heavy cocoon weight (SUB-11). By repeating backcross from 2010 to 2018, we obtained and stored backcross strain (B_n; n represents the number of generations) from third generation (B₃) to seventh generation (B₇). Comparing SUB-52, SUB-11 and each B_n by statistic method showed that B₆ was superior to other strains in terms of silk productivity. Although cocoon weight and cocoon shell weight in the latest backcross strain B₇ was significantly higher than that of SUB-52, there was no significant difference between B₇ and their recurrent parent SUB-11. We consider that B₇ was getting closer to SUB-11 and appropriate backcross should be limited until B₆. As for future research, we plan to improve the fertilization rate by using B_n for hybridization.