| More and more silkworms have been poisoned resulting from the contamination of Fluor gas. This phenomenon has caused huge economic loss. The relating government and scientists have paid more attention to it. Nowadays, a lot of researches and reports have been done to find out why and how the silkworm be poisoned. And many preventative measures have been carried out. One side, the research of the effect that Fluor brings to organism immunity has become more and more popular; on the other side, the research of the effect that fluorsis brings to silkworm has never been done. Therefore, in this thesis, the related research has been done. Below 3 points have been got as the main research results. They can provide theory evidences for preventing the silkworm from floursis and improving the silkworm immunity.1. To a certain extent, NaF can hold the immunity of silkworm cell. After being treated by NaF, the quantity of blood lymphocyte has decreased. The blood cells will decrease along with the increase of the NaF concentration. Comparing with matched group, if the NaF is 80mg/L, the quantity of the blood cell will decrease 37%; if the NaF is 160mg/L, the quantity of the blood cell will decrease 59%. The test also shows that, the phagocytic activity of the silkworm blood cell won't change obviously if it is treated by low concentration NaF. But if the NaF concentration is high, the result will be totally different. Comparing with the matched group, if the NaF is 80mg/L, the phagocytic activity will decrease 61.4%; if the NaF is 160mg/L, the phagocytic activity will decrease 71.6%. The result shows that high concentration NaF can hold the phagocytic activity of the silkworm blood cell and decrease the silkworm immunity. The test in vitro shows that, if the NaF is 100mg/L, the phagocytic activity of the silkworm will be held obviously.2. After being treated by NaF, the blood lymph blackening of the silkworm will be slow; this will decrease the immunity of the silkworm humor. Higher concentration the NaF is, slower the blackening is. And if the silkworm is treated by low concentration NaF, the activity of PO will be improved; if the silkworm is treated by high concentration NaF, the activity of PO will be hold. In vitro, the IC50 is 44.6mg/L. The activity of lysozyme and antisepsis will decrease along with the increase of the NaF concentration. After treating by 160mg/L NaF, the activity of lysozyme has decreased 72% and the activity of antisepsis has decreased 78% on the 7th day. Catalase is an important organism protective enzyme. After feeding certain concentration NaF on silkworm, the activity of catalase has increased in the silkworm blood. However, if in the condition of vitro, the activity of catalase can not be increased.3. For those silkworms with different anti Fluor abilities, if the silkworm has high anti Fluor ability, its immunity index will change little; if the silkworm has low anti Fluor ability, its immunity index will change much. After feeding 160mg/L NaF on silkworm, the quantity of the blood cell, the phagocytic activity, the phenol oxidase activity, the lysozyme activity and the antisepsis activity all have changes. And different kinds of silkworms change in different degree.NaF can hold the silkworm immunity obviously. If the silkworm has high anti-Fluor ability, the holding effect is weak; if the silkworm has low anti-Fluor ability, the holding effect is strong.
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