Yi Dengxia, Cui Shusong, Yang Limei, Fang Zhiyuan, Liu Yumei, Zhuang Mu, Zhang Yangyong
Key Laboratory of Horticultural Crops Genetic Improvement, Ministry of Agriculture/Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, P. R. China Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China.
Key Laboratory of Horticultural Crops Genetic Improvement, Ministry of Agriculture/Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, P. R. China.
J Insect Sci. 2015 Apr 5;15(1). doi: 10.1093/jisesa/ieu054. Print 2015.
Larval survival and oviposition behavior of three genotypes of diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), (homozygous Cry1Ac-susceptibile, Cry1Ac-resistant, and their F1 hybrids), on transgenic Bacillus thuringiensis (Bt) broccoli expressing different levels of Cry1Ac protein were evaluated in laboratory. These Bt broccoli lines were designated as relative low, medium, and high, respectively, according to the Cry1Ac content. Untransformed brocccoli plants were used as control. Larval survival of diamondback moth on non-Bt leaves was not significantly different among the three genotypes. The Cry1Ac-resistant larvae could survive on the low level of Bt broccoli plants, while Cry1Ac-susceptible and F1 larvae could not survive on them. The three genotypes of P. xylostella larvae could not survive on medium and high levels of Bt broccoli. In oviposition choice tests, there was no significant difference in the number of eggs laid by the three P. xylostella genotypes among different Bt broccoli plants. The development of Cry1Ac-susceptible and Cry1Ac-resistant P. xylostella on intact Bt plants was also tested in greenhouse. All susceptible P. xylostella larvae died on all Bt plants, while resistant larvae could survive on broccoli, which expresses low Cry1Ac protein under greenhouse conditions. The results of the greenhouse trials were similar to that of laboratory tests. This study indicated that high dose of Bt toxins in broccoli cultivars or germplasm lines is required for effective resistance management.
在实验室中评估了小菜蛾（Plutella xylostella L.，鳞翅目：菜蛾科）三种基因型（纯合Cry1Ac敏感型、Cry1Ac抗性型及其F1杂交种）的幼虫存活率和产卵行为，这些小菜蛾置于表达不同水平Cry1Ac蛋白的转基因苏云金芽孢杆菌（Bt）西兰花上。根据Cry1Ac含量，这些Bt西兰花品系分别被指定为相对低、中、高表达水平。未转化的西兰花植株用作对照。小菜蛾在非Bt叶片上的幼虫存活率在三种基因型之间没有显著差异。Cry1Ac抗性幼虫能够在低水平Bt西兰花植株上存活，而Cry1Ac敏感型幼虫和F1幼虫不能在其上存活。小菜蛾三种基因型的幼虫都不能在中、高水平Bt西兰花上存活。在产卵选择试验中，三种小菜蛾基因型在不同Bt西兰花植株上的产卵数量没有显著差异。还在温室中测试了Cry1Ac敏感型和Cry1Ac抗性型小菜蛾在完整Bt植株上的发育情况。所有敏感型小菜蛾幼虫在所有Bt植株上均死亡，而抗性幼虫能够在温室条件下表达低水平Cry1Ac蛋白的西兰花上存活。温室试验结果与实验室测试结果相似。本研究表明，西兰花品种或种质系中需要高剂量的Bt毒素才能有效进行抗性治理。
