Effects Of Deoxypodophyllo Toxin On Reproductive Systems In Mythimna Separate

Deoxypodophyllotoxin was one of the main insecticidal ingredients in Sabina vulgaris Ant,an insecticidal plant.The results of our previous studies had proven that Deoxypodophyllotoxin had excellent insecticidal activity against cabbage worm(pieris rapae), diamondback moth(Plutella xylostella), Mythimna Separate and other pests. In order to further reveal the mechanism of Deoxypodophyllotoxin,From the facts of histology and physiology, This paper studied effects of Deoxypodophyllotoxin on reproductive systems in and explored the mechanism of its growth and development inhibition by light microscope and electron transmission microscope, The main results are as follows:1 Deoxypicropolltoxin had obvious gowth inhibition function to larval of Mythimna separta. Results indicated that the pupation rate, eclosion rate, oviposition quantity and egg hatching rate decreased significantly, but the abnormal pupae rate increased.When the tested insects were treated at the dosage of 0.5 mg·mL-1, their oviposition quantity and egg hatching rate is 9.37 and 6.43% respectively.2 Deoxypicropodophyllotoxin has obviously influence on fecundity of Mythimna separta., Results indicated that the lifetime of adult and oviposition periods shortened, the oviposition quantity.egg hatching rate and larva survival rate decreased after deoxypicropodo- phyllotoxin was feed to the adult, male adult and female adult respectively.3 Deoxypicropodophyllotoxin inhibit the ovary and testis development of Mythimna separta W.the length of ovary tubes,wet weight of ovaries, the contents of DNA , RNA and the soluble protein in ovary obviously decreased after 0.3 mg/mL deoxypicropodophyllotoxin was feed to female adult. Combining with Histological observations showed that the nutritive cells and foillcle cells disappear; the density of cytoplasm has a dramatic decrease;the microvilli on the surface of oocyte obviously shorten and the yolk yelk subgranular loosely in treatment group ovary.as the arrangement of spermatogonia was loose, the cell division of primary spermatocyte and secondary spermatocyte was irregularly,the distribution of nucleoplasm particles wae abviously inhomogeneous,came about testis tubular reduced severely in the treatment group testis.4 Deoxypicropodophyllotoxin had different influence on testis enzymes.The activity of SDH,LDH and Na+-K+-ATPase in tested insects was inhibited significantly except Ca2+-Mg2+ -ATPase. Combined with the observational results of histology,deoxypicropodophyllotoxin made some injury to the male reproduction cell by inhibiting the activity of these enzymes. The activity of acid phosphatase (ACP) and alkaline phosphatase(AKP) was inhibited, and then activated gradually according to the exposure time. Deoxypicropodophyllotoxin caused injury in some degree in the treatment testis tissue which resulted in oligospermatism by inhibiting the activity of the two enzymes.5 Based on above results, it can be concluded that the mechanism of deoxypicropodo- phyllotoxin on the reproductive system of Mythimna separta is inhibit the ovary and testis development,and have influence of the metabolism of energy substances such as the contents of nucleic acid, the soluble protein and the fat and so on,which lead to the fecundity decreased...