寄生对橘小实蝇幼虫体内过氧化物酶活性的影响

Effects of Parasitism on the Activity of Peroxidase in the Larvae of Bactrocera dorsalis (Diptera: Tephritidae)

将被寄生后处于不同发育阶段的橘小实蝇幼虫解剖并除去体内切割潜蝇茧蜂虫体后,运用愈创木酚法测定橘小实蝇幼虫体内过氧化物酶活性的变化.结果表明：橘小实蝇2日龄幼虫被切割潜蝇茧蜂寄生后体内POD活性均比对照明显升高（P〈0.01）,寄生作用能诱导POD活性升高;随着寄主幼虫的虫龄增长,吸光值呈现明显波动现象,虫龄为72-120 h时POD活性处于最活跃水平,其中以72 h为最高;进入蛹期后（≥144 h）则酶活性水平极低.研究认为这种酶活性的变化揭示了橘小实蝇幼虫对寄生的一种典型生理防御行为,可为探讨二者之间的关系提供理论依据.

The guaiacol method was adopted to test the change of peroxidase （POD） activity in the larvae of B. dorsalis parasitized by P. incisi. The results show that the activity of POD in the parasitized larvae was distinctly higher than that in the unparasitized larvae at the same stage （P〈0. 01）, and this increase of POD was induced by the parasitism of P. incisi. ; that there was a bit change of POD activity from 0 to 48 h after parasitism, then a sharp change from 48 to 72 h with the rapid increase of OD value, but after maintaining a higher activity of POD from 72 to 120 h, there was finally a decrease after 144 h with the lowest activity of POD. It is concluded that this phenomenon can be regarded as a physiological defensive action of B. dorsalis larvae to the parasitism of P. incisi and also used to probe into the relationship between B, dorsalis and P. incisi.