【作者】 高明清；

【导师】 陈学新；

【作者基本信息】 浙江大学 ， 环境生物学， 2010， 博士

【摘要】 尽管转基因作物的安全性评价存在很大的争议,但是转基因作物已经成为一个全球性的杀虫剂。室内室外研究均表明转基因水稻能够有效控制鳞翅目害虫,但是在转基因水稻批准商业化之前,对其进行安全性评价是十分必要的。本论文分别选取了“转基因水稻克螟稻—褐飞虱—黑肩绿盲蝽”和“转基因水稻克螟稻—褐飞虱—稻虱缨小蜂”两条非靶标的食物链,旨在检测转Bt基因水稻表达的Cry1Ab毒蛋白能否在非靶标食物链中传递以及Cry1Ab毒蛋白对非靶标生物及其天敌的影响。结果如下：1 CrylAb毒蛋白在“克螟稻—褐飞虱—黑肩绿盲蝽”食物链中的传递褐飞虱6日龄的卵体内可以检测到Cry1Ab毒蛋白的存在,而且以褐飞虱卵为食物的黑肩绿盲蝽若虫可以检测到Cry1Ab毒蛋白的存在,但是并没有随着若虫龄期的发育而累积。同时,以褐飞虱一龄若虫为食物的黑肩绿盲蝽若虫和成虫体内均没有检测到Cry1Ab毒蛋白的存在。2转基因水稻对褐飞虱及其捕食性天敌生物学特性的影响取食转基因水稻的褐飞虱卵的发育历期被显著延长,但是黑肩绿盲蝽的发育历期并没有因为以取食转基因水稻的褐飞虱卵为食物而被延长。同时,以取食转基因水稻的褐飞虱卵为食物的黑肩绿盲蝽的存活率显著提高；而且,以取食转基因水稻褐飞虱的卵为食物的黑肩绿盲蝽的雌成虫体重也显著高于对照。3 Cry1Ab毒蛋白在“克螟稻—褐飞虱—稻虱缨小蜂”食物链中的传递及对稻虱缨小蜂连续代数的影响初羽化的稻虱缨小蜂成虫体内检测到了Cry1Ab毒蛋白的存在,但是对稻虱缨小蜂的产卵量并没有显著的影响。转基因水稻品系上稻虱缨小蜂雌蜂和雄蜂的第一代和第二代的发育历期均显著长于对照非转基因水稻品系,但是从第三代至第十一代稻虱缨小蜂的发育历期并不是总是长于对照品系。此外,转基因水稻和非转基因水稻品系上稻虱缨小蜂从第一代至第十一代的后代性比均呈现偏雌性。4 Cry1Ab毒蛋白对稻虱缨小蜂成蜂寿命的影响Cry1Ab蛋白可以在以蜂蜜混合不同浓度Cry1Ab纯蛋白饲喂的稻虱缨小蜂体内检测到；以转基因水稻饲养褐飞虱卵为寄主,对稻虱缨小蜂雄成虫寿命没有明显的影响；以克螟稻2饲养褐飞虱卵为寄主的稻虱缨小蜂雌成虫寿命要显著低于秀水11和克螟稻1饲养褐飞虱卵为寄主的稻虱缨小蜂雌成虫；来自克螟稻2品系的稻虱缨小蜂与来自秀水11和克螟稻1品系的稻虱缨小蜂存活率差异显著,而来自克螟稻1品系的稻虱缨小蜂与来自秀水11品系的稻虱缨小蜂存活率差异不显著；蜂蜜和蜂蜜混合Cry1Ab纯蛋白饲养的稻虱缨小蜂成蜂的寿命以及存活率差异均不显著;Cry1Ab纯蛋白浓度对稻虱缨小蜂寿命的影响差异不显著。5转Bt基因水稻对田间稻飞虱着卵量及其天敌的影响两年时间两个地点三个水稻品系上的稻飞虱平均每分蘖着卵量趋势基本一致,并且田间的高峰期均大概持续2周左右;两年时间两个地点三个水稻品系上飞虱卵被捕食率和被寄生率的趋势也基本一致。更多还原

【Abstract】 Although theoretical approaches to assessing risk on non-target organisms in insect resistant transgenic crops expressing Bt toxin has been debating over last decades, Bt crops have become a major insecticide worldwide. Bt rices can effectively control lepidopteran pests under laboratory and field conditions. Before release, transgenic Bt rice need to undergo a risk assessment process to avoid harm to the environment. In the present study, we choose two non-target food chains (Bt rices—Nilaparvata lugens—Cytorhinus lividipennis and Bt rices—N. lugens—Anagrus nilaparvatae) to evaluate 1) biotransfer and bioaccumulation of Cry1 Ab toxin in a non-target food chain, and 2) the effect of Cry1 Ab on the fitness parameters of nontarget organisms. Results are as follows:1. Biotransfer and bioaccumulation of Cryl Ab on non-target food chain of Bt rices—Nilaparvata lugens—Cytorhinus lividipennisBt toxin Cryl Ab could be detected in the 6-day-old eggs. Moreover, the presence of Cry1 Ab toxin was detected in C. lividipennis nymphs after preying on Bt rice-fed N. lugens eggs, but not accumulate in C. lividipennis as the stage developed. However, no Cry1 Ab was detected in nymphs and adults of C. lividipennis after preying on Bt rice-fed N. lugens first instar nymphs.2. Effect of Bt rices on fitness parameter of N. lugens and its predatorAlthough egg developmental time of N. lugens was significantly longer when N. lugens fed on Bt rice, developmental time of C. lividipennis was not significantly different between individuals preyed eggs of N. lugens fed on Bt and non-Bt rice. Survivorship of C. lividipennis increased significantly when it preyed on eggs of N. lugens feeding on Bt rice. Furthermore, the body weight of C. lividipennis female adult increased significantly as compared to the control.3. Biotransfer and bioaccumulation of Cry1 Ab on non-target food chain of Bt rices—N. lugens—A. nilaparvatae and multi-generation effects of Bt rice on A nilaparvatae ELISA test confirmed that Cry1 Ab toxin could be detected in newly-eclosed parasitoid adults. However, no significant effect on fecundity of A. nilaparvatae was observed between Bt or non-Bt rice. Developmental times of both genders of A. nilaparvatae in both genders were significantly prolonged from first generation to second generation when host eggs laid in Bt (KMD1 and KMD2) rice lines. However, the developmental times of A. nilaparvatae on eggs in KMD1 and KMD2 were not always prolonged from third generation to eleventh generation as compared to the control rice line. Furthermore, progeny sex ratio of A. nilaparvatae from first generation to eleventh generations in three rice lines was always female-biased.4. Effect of CrylAb on the longevity of A. nilaparvataeCryl Ab protein could be detected from A. nilaparvatae adults when they reared on honey mixed with different concentrations of purified Cry1Ab protein. Longevity of male A. nilaparvatae adults were not affected by eggs of N. lugens feeding on Bt or non-Bt rice. The longevity of female A. nilaparvatae adults from eggs of N. lugens feeding on KMD2 rice were shorter than thosefrom eggs of N. lugens feeding on XS11 and KMD1 rice. Survival rate of A. nilaparvatae adults from eggs of N lugens feeding on KMD2 rice were singificantly different from those from eggs of N. lugens feeding on XS11 and KMD1 rice. No significant effects were observed on longevity and survival rate of A. nilaparvatae adults reared on honey mixed with purified Cry1Ab protein compared to those reared on honey. Different concentrations of purified CrylAb protein have no effect on longevity of A. nilaparvatae adults.5. Effect of transgenic Bt rice on population dynamics of N. lugens eggs and its natural enemy in paddy fieldThe trends of N. lugens eggs population dynamics were almost the same on three different rice lines at Zhejiang University Experiment Farm and Fuyang Experiment Farm in 2008 and 2009. The peak of number of N. lugens eggs lasted about two weeks in paddy field. The trends of prey-upon rate and parasitism rate of N. lugens eggs were basically the same on three different rice lines at Zhejiang University Experiment Farm and Fuyang Experiment Farm in 2008 and 2009.更多还原