| To breed silkworm varieties with higher humidity tolerance, directional breeding under high humidity circumstances was carried out for 4 years in this experiment, and the humidity tolerance of four silkworm varieties of Japanese strain was improved. The results showed that through continuous high humidity motivation for eight generations,all the larva-pupa survival rate of the four varieties increased. We reared four high humidity motivated strains and original parent strains in condition of high humidity, and the results showed that all the larva-pupa survival rate of high humidity motivated strains were higher than that of original parent strains. The larva-pupa survival rate of “Yan 7”was improved greatly, from 38.60% to 72.13%. We used the high humidity motivated strains to obtain the improved first hybrid of 野Yue
can No.6冶, reared it and original first hybrid in condition of high humidity, the results showed that the survival rate and economic characters improved significantly. Accordingly, the experimental results demonstrate that high humidity motivation for several generations may improve the high humidity tolerance of silkworm varieties, and breed new silkworm materials with high humidity tolerance. |
