Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou University Yangzhou 225009 P.R.China;
Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou University Yangzhou 225009 P.R.China;
Cotton Research Institute Chinese Academy of Agricultural Sciences Anyang 455000 P.R.China;
Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou University Yangzhou 225009 P.R.China;
Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou University Yangzhou 225009 P.R.China;
Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou University Yangzhou 225009 P.R.China;
Bt cotton; external nitrogen application; urea concentration; Bt toxin; protein metabolism;