【作者】 蒋芸芸；

【导师】 王世贵；

【作者基本信息】 杭州师范大学 ， 动物学， 2007， 硕士

【摘要】 寄生蜂对寄主的调节是一个复杂的过程,大多数内寄生蜂产卵时同时注入寄生因子(如PDV、毒液、萼液),以及卵孵化过程中会释放出的畸形细胞和幼蜂分泌物等,从而影响或调控寄主的的生长发育、代谢及繁殖等生理活动,使之有利于寄生蜂发育、确保其后代能顺利在寄主体内完成发育的。本文以半闭弯尾姬蜂和寄主小菜蛾为研究对象,研究了半闭弯尾姬蜂对寄主的生理调控,主要包括以下几点内容：1.半闭弯尾姬蜂对小菜蛾幼虫生长发育的影响选取2龄、3龄的小菜蛾幼虫,半闭弯尾姬蜂寄生以后,对寄主体重增长、发育历期、死亡率、结茧率和致死率等进行了研究。结果显示,两种龄期的小菜蛾幼虫被寄生后,体重增加缓慢,发育历期延长,死亡率上升,寄生组和对照组致死率差异显著(P<0.01)。同时,实验数据显示3龄幼虫更适合于半闭弯尾姬蜂寄生。2.半闭弯尾姬蜂对小菜蛾幼虫血淋巴蛋白的影响采用Bradford方法测定了小菜蛾3龄幼虫被半闭弯尾姬蜂寄生后血淋巴中蛋白的含量。结果显示,寄生后寄主血淋巴蛋白含量急剧下降至4.35±0.15mg/mL,寄生后不同时间蛋白含量差异显著(P<0.01)。SDS-PAGE检测显示蛋白种类也有所改变,寄生后期的主要蛋白种类相对较多,第5天出现了几条特异性蛋白条带,分子量分别为140.90kDa,89.44kDa,54.02kDa。对寄生后寄主血淋巴中的游离氨基酸含量进行了液相色谱分析,结果显示寄生后寄主血淋巴游离氨基酸的总量下降了,不同种类游离氨基酸的含量也存在很大的不同。3.半闭弯尾姬蜂对小菜蛾呼吸代谢的影响每天在同一时间段、相同温度下,对小菜蛾幼虫进行了CO2呼吸量的测定。结果显示,寄生后小菜蛾幼虫的CO：呼吸量发生了明显的变化,总体上随着虫体的长大仍呈上升趋势,且CO2呼吸量与幼虫体重存在一定的相关性,但寄生后的呼吸量要低于对照组,可能是蜂毒在抑制寄主的呼吸代谢上发挥了重要作用。4.半闭弯尾姬蜂对小菜蛾的体液和细胞免疫抑制作用通过血淋巴体外黑化实验来观察小菜蛾被半闭弯尾姬蜂寄生后的黑化百分率。结果显示,随着寄生时间的延长,黑化百分率在下降,而且体液免疫抑制因子——酚氧化酶活性也因寄生而明显降低,显示半闭弯尾姬蜂有较强的寄主抑制作用。采用离体注射和活体注射方法,将蜂毒加至小菜蛾幼虫的血淋巴中,观察血细胞形态的变化。结果显示,小菜蛾参与细胞免疫的主要血细胞(颗粒细胞和浆细胞)在一定程度上都发生了形态的改变和活性的丧失,表明了寄生蜂毒液在此发挥了明显的作用。更多还原

【Abstract】 The regulation of parasite to host is a complex process. Parasitic factors (PDV, venom, calyx fluid) injected by the majority of the parasitic wasps which are spawning as well as the teratocytes released by their eggs that are hatching seriously disturb the physiology, biochemistry, survival and reproduction of the host. In this paper, Diadegma semiclausum and its host Plutella xylostella were studying objects. On the basis of three parasitism factors having been studied clearly, the physiological regulation of Diadegma semiclausum to its host was studied. The major contents are as follows:1.Effects of Diadegma semiclausum on the development of two kinds of instar larvae of Plutella xylostellaThe growth of mass, the developmental time as well as the change of mortality rate, rate of cocoon formation and lethiferous rate of2nd,3rd instar host larvae and that which had not been parasitized were compared. The results showed the slow growth of mass of the two instar host larvae, the longer developmental time, and the great growth of mortality rate with remarkable difference, also the remarkable difference of the lethiferous rate of parasitism group and non-parasitized controls. The experiment datas showed that the3rd instar larvae was fit for Diadegma semiclausum to parasitize better.2. Effects of Diadegma semiclausum on the protein in hemolymph of Plutella xylostellaThe protein content in the hemolymph of Plutella xylostella parasitized by Diadegma semiclausum had been tested by means of Bradford. The results showed that the content of the protein decreased sharply to4.35±0.15mg/mL. The result of SDS-PAGE electrophoresis showed that the kinds of the protein also changed, with more kinds of major protein in the later period after being parasitized. Several specific proteins bands appeared on the5th day, with molecular weight of140.90kDa、89.44kDa、54.02kDa. The content of the free amino acids in the hemolymph had been analysed by HPLC. The whole content of the amino acids decreased, and the contents of different free amino acids had great differences.3. Effects of the host respiratory metabolism parasited by Diadegma semiclausumWe examined the host CO2production at the same time and the same temperature everyday, then weight the lavae.The results showed that CO2production changed apparently after wasp oviposition,but also increased with the host growing, and the CO2production had a relativity with the host body mass. 4. The restrain effect of Diadegma semiclausum on the host humour and cell immunityThe melanize rate of the hemolymph of Plutella xylostella parasitized by Diadegma semiclausum was observed in vitro. The results showed that the melanize degree decreased, following the prolonging of the time after being parasitized. Furthermore, the fact that the activity of phenoloxidase (PO) being restrained was also confirmed. And the PO activity between the two groups had a remarkable difference.Then we observed the ovary and venom of Diadegma semiclausum and the effects on host hemocytes conformation when injected by Diadegma semiclausum venom in vitro and in vivo.The results showed the conformation of two major immunity hemocytes (granular and plasmatocytes cells) in host hemocytes changed partially, for example, the pseudopod of the plasmatocytes was not obvious, in addition, cytolysis was observed.更多还原