The oral toxicity of the transgenic Bt+CpTI cotton pollen to honeybees (Apis mellifera)
Biao Liu, Chang Shu, Kun Xue, Kexin Zhou, Xiaogang Li, Doudou Liu, Yangping Zheng, Chongren Xu
State Key Biosafety Laboratory, Nanjing Institute of Environmental Sciences (NIES), Ministry of Environmental Protection of China, Nanjing, Jiangsu 210042, China.
Transgenic insect-resistant cotton has been planted in China in a large scale and may have adverse impacts on honeybees. Pollens from the transgenic Cry1Ac+CpTI cotton Zhong-41 and the parental cotton Zhong-23 were collected from the field and their impacts on adult worker bees were assessed. Experimental results showed that Zhong-41 pollen had no acute oral toxic effect on worker bees. No significant differences were observed in the superoxide dismutase activity or in the longevity of worker bees fed with diets containing the two cotton pollens. The main reasons for the outcome may be the low expression level of the transgenic proteins Cry1Ac and CpTI in the pollen of Zhong-41 as well as the substantial equivalence in the amounts of gross protein and soluble saccharides for the two cotton pollens. The implications of these results are discussed and further work to be carried out is put forward.