Studies On The Resistance Of Bombyx Mandarina Moore

We used the eggs and larvae of every instar of Bombyx mandahna Moore to investigate their adaptability in natural conditions. After the comparison with Bombye mori L, we found that there existed a difference of resistance between them. We fed fifth instar larvae with 80ppm NaF to induce the transcriptional expression of CYP450, cloned its fragments and got the whole sequence of P450 of Bombyx mandarina Moore.The results showed that natural elimination mainly took place at younger period, especially at first instar. There were some relationships between the development of Bombyx mandarina Moore and effective accumulated temperature, which meant that only if the effective accumulated temperature reached a fixed value could it accomplish a certain stage. We also found that the effective accumulated temperature of Bombyx mandarina Moore was less than that of Bombyx mori L whenever in larval period or pupal period.After feeding Bombyx mandarina Moore and Bombyx mori L with BmNPV and w-BmNPV, we found that a majority of Bombyx mandarina Moore with weak resistance fell ill quickly, while partial individuals with stronger resistance didn't fall ill even after longer period of treatment, which showed the resistance among individuals of Bombyx mandarina Moore was different; the whole resistance of Bombyx mori L was strong for falling ill at later period, but didn't reach the level of individual Bombyx mori L.The resistance of Bombyx mandarina Moore to pesticide is far stronger than that of Bombyx mori L. After fed with pesticide, partial Bombyx mandarina Moore turned from fourth molting silkworm to third molting or spin ahead, whereas the resistance of Bombyx mori L was too weak that they couldn't survive even at terribly low pesticide concentrations. The resistance of Bombyx mandarina Moore to UV was similar to pesticide. After the radiation of UV, partial Bombyx mandarina Moore would show a decrease in moultine or spin ahead; and the longer the radiation time,the greater the influence on them.Through the comparison of complete sequence of CYP450 between Bombyx mandarina Moore and Bombyx mori L, we found that their homologue was high up to 99%. Through the comparison of the sequence of amino acid, we found that there was only a amino acid difference between them; the site 35 of Bombyx mandarina Moore was His, while in Bombyx mori L it was Tyr.