论文标题:Bt杀虫蛋白和转基因抗虫棉花对棉铃虫及其天敌中红侧沟茧蜂的影响
Effects of Insecticidal Protein from Bacillus Thuringiensis and Transgenic Cotton on Helicoverpa Armigera H(?)bner and the Parasitoid, Microplitis Mediator Haliday
论文作者 刘小侠
论文导师 张青文；赵建周,论文学位 博士,论文专业 农业昆虫与害虫防治
论文单位 中国农业大学,点击次数 103,论文页数 111页File Size10207k
2005-05-01论文网 http://www.lw23.com/lunwen_4405942/ 棉铃虫;中红侧沟茧蜂;Bt CryIAc杀虫蛋白;转CryIAc单价基因抗虫棉;转CryIA+CpTI双价基因抗虫棉;棉铃虫核型多角体病毒
Helicoverpa armigera; Microplitis mediator; Bt CrylAc; transgenic crylAc cotton;transgenic crylA + CpTI cotton; HaNPV
转Bt杀虫蛋白(ICP)基因抗虫棉的广泛种植有效控制了棉铃虫(Helicoverpa armigera Hubner)的危害,但转基因抗虫作物并非为自然界天然存在的物种,这些作物的培育和大面积种植可能直接或间接地影响农田生态系统中其它有益生物。本论文以棉铃虫为寄主,在实验室系统研究了Bt ICP(CrylAc)和转基因抗虫棉对中红侧沟茧蜂(Microplitis mediator Haliday)的直接和间接影响。主要结果如下: 1、中红侧沟茧蜂成蜂产卵行为对寄主大小有显著的选择性。成功寄生率随寄主体重的增加而降低,大于14mg的棉铃虫幼虫不适宜该寄生蜂产卵。寄主体重与中红侧沟茧蜂茧重、茧重与成蜂重以及成蜂重与成蜂寿命之间存在极显著的正相关,而寄主体重与中红侧沟茧蜂的卵和幼虫期存在负相关,茧期不受寄主大小的影响。棉铃虫取食含CrylAc的饲料时,幼虫发育历期延长,化蛹率和蛹重降低,适合中红侧沟茧蜂寄生的时间段延长。 2、以室内多年饲养和田间棉铃虫品系为寄主,研究亚致死浓度的Bt CrylAc杀虫蛋白对两个品系棉铃虫和中红侧沟茧蜂生长发育的影响。结果表明:Bt CrylAc杀虫蛋白能有效抑制两个棉铃虫品系幼虫的生长,显著降低棉铃虫蛹重;两个品系棉铃虫均对转crylA+CpTI抗虫棉高度敏感;当寄主一直取食,或者在被寄生前12小时开始取食含Bt CrylAc杀虫蛋白的饲料时,与对照相比,中红侧沟茧蜂的卵-幼虫历期延长,茧重和成虫体重降低,成虫寿命缩短,但对茧期没有显著影响。 3、从感染了Bt CrylAc杀虫蛋白的寄主体内繁殖的F_1代寄生蜂能够寄生健康棉铃虫,F_2代寄生蜂的生物学特性与对照相比没有显著差异。被中红侧沟茧蜂寄生后,寄主血淋巴黑化反应被抑制,酚氧化酶活性和血细胞浓度降低:Bt CrylAc杀虫蛋白对棉铃虫血淋巴黑化反应没有影响:Bt CrylAc杀虫蛋白对棉铃虫酚氧化酶活性、血细胞浓度的影响随Bt处理时间不同而不一致;通过ELISA测定,在棉铃虫体内和棉铃虫血淋巴内检测到了Bt CrylAc杀虫蛋白,但在中红侧沟茧蜂幼虫体内没有检测到Bt CrylAc杀虫蛋白。 4、新羽化的中红侧沟茧蜂成虫取食含Bt CrylAc杀虫蛋白的蜂蜜水后,与对照相比,寄生蜂的雌蜂和雄峰寿命均没有被影响;取食含Bt CrylAc杀虫蛋白蜂蜜水的中红侧沟茧蜂,能够产卵寄生健康棉铃虫,子代寄生蜂的卵-幼虫历期、茧期、茧重和成虫体重、成虫寿命均没有被影响。
Interactions among the cotton bollworm, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae), its larval parasitoid Microplitis mediator (Haliday) (Hymenoptera: Braconidae), and CrylAc insecticidal protein of Bacillus thuringiensis Berliner or transgenic cotton expressing CrylAc and CrylA + CpTI (cowpea trypsin inhibitor) were evaluated under laboratory conditions. The following were results:1. Host (H. armigera) size had significant influence on oviposition of the female parasitoid, and the parasitization rate decreased as the host size became large. Host larvae over 14 mg were difficult to be parasitized. The host weight at time of parasitizationg was positively related with cocoon weight of the parasitoid, cocoon weight was positively related with adult weight of the parasitoid, and the longevity of the adult was positively related with the weight of the parasitoid adult, but the host weight at time of parasitization was negatively related with egg incubation and larval duration. However, the host weight did not significantly affect cocoon duration. The growth of H. armigera larvae was delayed and the pupation rate and pupal weight decreased when they were fed on diet containing CrylAc protoxin. Due to the slower growth rate of the host larvae, the time available for parasitization of H. armigera by M. mediator increased when the host larvae were reared on diet containing CrylAc protoxin.2. The effects of Bt protein on laboratory and field populations of H. armigera and the parasitoid were tested. When M. mediator parasitized hosts reared on diet containing CrylAc protoxin, their egg and larvae durations were delayed. Pupal weight, new emerging adult body weight and adult longevity were also significantly decreased. When hosts fed on diet containing CrylAc protoxin for 12 h before parasitism and after parasitism, the effects on M. mediator were similar to those which hosts were continually treated with Bt toxin. In comparison to control, the larval weight and pupal weight of cotton bollworms were decreased significantly when their larvae fed on diet containing Bt toxin. The cotton bollworm of both laboratory and field populations were susceptible to transgenic cotton expressing Cry 1A plus CpTI.3. When adult M. mediator parasitized the host larvae that fed on diet containing CrylAc toxin, their offspring"s eggs and larvae were significantly delayed and pupal weight and adult weightwere also significantly less compared with the control. The F_2 female parasitoid from the host which fed on diet containing 8 μg/g CrylAc protoxin could oviposit on a healthy host, and her biological parameters (egg-larval period, pupal weight and adult weight), parasitism rate, abnormal pupal rate and adult emergence were not affected significantly. Phenoloxidase activity of parasitized or unparasitized host was inhibited significantly when host fed on Bt-diet(8 μg/g) Melanogenesis rate of parasitized host larvae was inhibited whether larvae fed on Bt-diet(8 μg/g) or normal diet when compared to unparasitized host. For both non-parasitized and parasitized host, the concentration of hemocytes of larvae fed on Bt-diet (8 μg/g) for 24 h and 48 h was decreased significantly when compared to control. CrylAc toxin was detected in larvae and hemolymph of H, armigera, but no CrylAc toxin was detected in the larvae of M. mediator.4. The longevity of female and male parasitoids was not significantly affected when newly emerging wasps fed on honey solutions containing three different concentrations of CrylAc protoxin (125, 250, 500 μg/ml). When female parasitoids fed on honey solutions containing CrylAc, their offspring"s egg and larval development period, pupal weight, length of pupation, adult weight and adult longevity did not change significantly in most of the treatments compared with the control.5. Two major transgenic cotton cultivars used in Hebei province of northern China, DP99B (Bollgard), carrying the cryIAc gene, and SGK321, carrying both crylA and CpTI genes, were used for testing the effects on M. mediator. The results ind
|
