咪唑类化合物YA20对家蚕眠性和变态的影响

EFFECTS OF YA20, AN IMIDAZOLE DERIVATIVE, ON THE MOLTINISM AND METAMORPHOSIS OF THE SILKWORM, BOMBYX MORI

本文探讨了咪唑类化合物YA20对家蚕第四龄及熟蚕的生理效应。(1)第四龄48小时的蚕经结扎去头,导致去头蚕产生蛹态,用1000ppm的YA20或50-1000的保幼激素类似物738的丙酮液分别浸渍处理,去头蚕在蜕皮后保留幼虫态,若用100-1000ppm的YA20丙酮液浸渍熟蚕,则熟蚕蜕皮后产生幼虫态,表明YA20具有保幼激素类似物的效应。(2)四龄蚕初期连续添食YA20 48小时,可有效诱导三眠蚕,与正常四龄蚕相比,三眠蚕血淋巴中蜕皮激素的滴度高峰期被明显推迟。但是,用植源性蜕皮激素及YA20同时添食,则可完全抑制三眠蚕的发生,还讨论了YA20在不同条件下产生的抗保幼激素、抗蜕皮激素及保幼激素类似物等三种作用。

The effects of YA20, an imidazolc derivative, on the growth and metamorphosis of the 4th and 5th instar larvae of the silkworm, have been investigated. 1. After decapitation of the larvae at 48 hrs in 4th instar the headless larvae later molted into pupae. But the larval state could be retained when the headless larvae were dipped by the acetone solution of YA20(1000ppm) or a JHA, JH-25 (50-1000ppm). In addition, a larval-larval molt was induced instead of pupation when the 5th instar larvae shortly before spinning were dipped by an acetone solution containing 100-1000ppm of YA20. The results clearly showed that YA20 functioned as a JHA under these conditions. 2. The trimoltism was induced when the 4th instar larvae were fed on YA20 treated mulberry leave from 0-48 hrs. As compared with the pattern of hcamolymph ccdyslcroid tiler in the normal 4th instar larvae, the peak of ccdystcroid liter was rcmakably delayed in the trimoltism larvae. However, the occurancc of the trimoltism was completely inhibilcd when the 4lh instar larvae were ingested with both the phylogenous ccdystcroids and YA20. The agonislic and antagonistic hormone actions shown by YA20 under different conditions were discussed.