Sống bằng cây cỏ côn trùng là trách nhiệm đối với tổn thất lớn trong cây trồng. Đối với việc kiểm soát five qua dịch hại Nhiều thập kỷ đã-được Phần lớn đã được hoàn thành bởi việc sử dụng thuốc trừ sâu hóa học, mặc dù aussi thành công Một số ĐÃ Been đã đạt được hướng tới sản xuất cây có sức đề kháng tăng cường sử dụng Mức độ nội sinh giống cây trồng thông thường (tức là chủ nhà máy điện trở) và trong kỹ thuật in vitro | 13 The role of insect-resistant transgenic crops in agriculture L. Jouanin and . Gatehouse Summary Phytophagous insects are responsible for major losses in crops. For the past five decades pest control has been accomplished largely by the use of chemical pesticides although some success has also been achieved towards producing plants with enhanced levels of endogenous resistance using conventional plant-breeding . host-plant resistance and in vitro techniques. Recent technologies such as plant genetic engineering provide breeders with the opportunity for introducing resistance genes from foreign species into crop plants. Different approaches have been considered to obtain such plants through the expression of entomotoxic proteins. The main strategy to date has been based on the expression of endotoxins Cry originating from the soil bacterium Bacillus thuringiensis Bt with the commercialization of such crops in the USA since 1995. However in order to enlarge the spectra of activity against insects and to co-express different toxins in transgenic crops screenings for new entomotoxic proteins of plant bacterial and insect origin have become necessary and some genes encoding such toxins have already been introduced into crops and tested against selected insect pests. The state of the art of these different strategies is considered in this chapter. Introduction Pest control is accomplished largely by the use of chemical pesticides however losses in the major crops remain important 1 . In addition major problems related to the use of these products have been reported the most important being detrimental impacts on the environment such as pollution of land and water tables toxicity towards nontarget organisms and accumulation in food chains. Thus it is necessary to develop more environmentally benign methods of crop protection. The use of other types of pest control measures such as breeding for resistant varieties modified agricultural practices biological .
