【作者】 薛珍；

【导师】 王志英； 詹亚光；

【作者基本信息】 东北林业大学 ， 林木遗传育种， 2004， 硕士

【摘要】 本文对转Bt C肽+蜘蛛杀虫肽的白桦进行杀虫性测定，对取食对照和转基因植株舞毒蛾幼虫的死亡率、体重降低率、蜕皮指数、幼虫各龄级历期等指标进行了分析，证明外源基因已经成功插入白桦基因组中，并且能够表达杀虫蛋白。 转基因植株能够明显延长幼虫各龄级的历期，对舞毒蛾1龄幼虫的历期延长4.38～5.73天；延长2龄幼虫的历期0.32～0.91天；延长3龄幼虫的历期0.62～1.08天；食对照组的幼虫绝大多数能够发育到5龄，完成幼虫期，而食转基因植株的幼虫无一发育到5龄。转基因植株能够明显抑制幼虫体重的增加，10天时，对照幼虫与处理幼虫体重相差不明显；20天时，对照幼虫体重是处理幼虫体重的2.41～3.59倍；30天时，对照幼虫体重约是处理幼虫体重的5倍；40天时，对照幼虫是处理幼虫体重的6.75～7.43倍；随取食时间延长转基因植株对舞毒蛾幼虫体重的抑制效果明显。转基基植株具有杀灭幼虫的作用，在实验中处理幼虫最终死亡率最高，能达到95.89％，是对照幼虫死亡率的4.1倍，实验第1～7天和第29～35天是幼虫死亡的密集期，处理幼虫多数在此时间段内死亡。转基因植株能够延迟幼虫蜕皮，降低幼虫蜕皮指数，实验30天时对照幼虫蜕皮指数是3.323；处理幼虫蜕皮指数在2.933～3.038之间，并且处理幼虫无一能够完成幼虫期达到化蛹。转基因植株能够降低幼虫的食叶量，3天时对照幼虫的食叶量比处理幼虫的食叶量多0.105293～0.137504克；21天时对照幼虫食叶量比处理幼虫食叶量多0.529094～0.64103克，随取食时间的延长，对照幼虫的食叶量与处理幼虫的食叶量差别更大，转基因植株的抑制作用更明显。经过单株测定的转基因植株表现出不同的杀虫能力。 外源基因对舞毒蛾幼虫的杀虫机理在于破坏幼虫的中肠组织，影响幼虫的取食，使幼虫取食量减少，甚至终止取食；中肠细胞间隙增大，细胞核遭受破坏；围食膜与中肠细胞之间出现空隙，甚至脱落，围食膜不再完整；中肠组织脱落，成为一个严重变形的残架。更多还原

【Abstract】 In this paper, we determined the toxicity of transgenic Betula platyphylla with Bt+spider peptide gene. Larvae of Lymantria dispar were feed on leaves of transgenic Betula platyphylla with Bt+spider peptide gene, The mortality, reduced ratio of weight, ecdysis index and schedule time of every instar. The results showed that the foreign genes had integrated into the genome of Betula platyphylla, and expressed.The transgenic Betula platyphylla could significantly extend scheduled time of every instar. 4.38~5.73d was extended for 1st instar, 0.32~0.91d for 2nd instar and 0.62-1.08d for 3rd instar. Most of controlled larvae could develop into 5 1 instar and complete the development of larva, while none for treated larvae. The transgenic Betula platyphylla could restrain the increase of the weight of larva, and this function was more and more significant with the increase of the time of feeding. There was no significant difference between the weight of controlled and treated 10-d old larvae. However, by 20d, the weight of controlled larvae was 2.41-3.95 times of that of treated larvae, and about 5 times by 30d, 6.75-7.43 times by 40d. The transgenic Betula platyphylla could kill larva. The total mortality of treated larvae was 95.89%, which was 4. Itimes of that of controlled larvae. The mortal peaks of larvae wasl-7d and 29-35 d, in which most of treated larvae was killed. The transgenic Betula platyphylla could reduce the ecdysis index of larvae. The ecdysis index of controlled larvae was 3.323 by 30d, while 2.933-3.038 for the treated. The transgenic Betula platyphylla could reduce the feeding of larvae. With the increase of the time of feeding, the difference of food taken between the controlled and treated became larger. The food of controlled larvae taken was 0.105293-0.13750 grams than that of the treated by 3 d. and 0.529094-0.64103 grams by 21d.The toxicity of individuals of the transgenic Betula platyphylla was different.Foreign gene could destroy larva’s mid-intestine, and reduce its appetite. Observation by microscope showed that the gaps between mid-intestine cells was extended in treated larvae, and the nucleus were destroyed, the gap between peritrophic membrane and mid-intestine cells was appeared, parts of peritrophic membrane was broken off from mid-intestine cells.更多还原