【摘要】 通过一系列组织学观察和生物化学测定,研究了灭幼脲在粘虫Mythimna separata(Walker)雌蛾体内及其所产卵内的作用及影响。灭幼脲(50ppm)经雌蛾连续取食后,卵巢中DNA、RNA的合成及卵巢对血淋巴中蛋白质的吸取均被促进,卵巢细胞核中DNA、RNA及蛋白质的含量均比正常雌蛾增加,卵巢发育及卵子形成亦被促进,产卵量正常。粘虫生殖系统未受灭幼脲的抑制。胚胎发育阶段细胞核及线粒体中DNA的含量均因雌蛾取食灭幼脲而降低,但胚胎发育并不中断,幼虫分化可达黑头期。灭幼脲导致粘虫所产卵不能孵化的主要原因在于幼虫分化过程中体壁及气管系统的形成受到严重抑制。体壁皮细胞缩小呈扁平形,无细胞核,连成线状,有断裂;原表皮缺乏或极薄。虫体内无气管分布。幼虫死于卵壳内。灭幼脲的不育作用和直接杀卵作用实质上都是对正在分化幼虫中几丁质合成的抑制。本文对灭幼脲的毒理机制进行了讨论。更多还原

【Abstract】 Diflubenzuron inhibits reproduction of the armyworm Mythimna separata (Walker) when the female moths were fed continuously with sucrose solution containing 50 ppm diflubenzuron. The activity of corpora allata of adults was adversely affected, but the vitellogenin synthesis of fat body, ovarian development and oogenesis could still proceed normally. The levels of DNA, RNA and protein in the cell nuclei of the ovaries were found to increase. However, no larvae would hatch from the eggs. It was observed that treatment of the adults or eggs with diflubenzuron did not influence the general course of embryonic development, but it had detrimental effects on the formation of integument and tracheal system of the developing embryos. The epidermal cells in the integument became flattened, smaller in size, and without nuclei. The procuticle became very thin or vanished. The tracheal trunks could not form and the respiratory function of the embryo could not perform normally. As a result, the embryos would die within the chorion. The DNA level in the nuclei and mitochondria of the embryos was found to decrease. It seems that sterilization in the armyworm may result in part from inhibition of DNA synthesis besides the inhibition of chitin synthesis.更多还原