Agrobacterium Tumefaciens-Mediated Transformation Of YZ₁ For Three Kinds Of Bt Genes

Upland cotton(Gossypium hirsutum L.) is one of most important economic crops in China,but also one crop tends to infested by many kinds of pests,with the damage of 15%～20% every year.Insect pest has become one of the the main factors of influence of cotton production.Over the past decades pesticides are widely used in the prevention and control of the pests,which have caused series problems such as environmental pollution, ecological unbalance.Tranditonally,the Application of insect-resistant cultivar based on morphological and biochemical properties is helpful to get good economic and social benefits by reducing the investment of pesticides, With the development of economic and society, modern agriculture require Cotton varieties more quality,such as High yield,high quality of fiber,disease resistance,insect resistance,drought resistance and so on.Because of narrow genetic basis, it is difficult to improve the insect resistance furtherly through traditional hybrid breeding methods in China.The development of biological technology provide an improtant way for insect -resistant breeding.In genetic engineering,a few resistant genes have been windly used to genetically improve cotton resistance to insect,which includ Bacllus thuringensis(Bt),Protease Inhibitors(pI) genes,Amylase inhibitors genes (AI),Lectin gene etc.In this study three Bt gene (CryIC, CryIIA, Cry9C) were transformed into YZ11 to improve the level of insect resistance through agrobacterium-mediated mathod.The hypccotyl of YZ1 and C312 were chosesed to be infected by EHA105 which carry the three Bt genes in this research,and then cultivated on screening culture medium containing 0.1mg/L2,4-D+0.1mg/L KT.Experiments show that callus can be available quickly.however,regenerability of embryonal callus varied differently between YZ1 and C312 in differernial medium four months later. Callus of YZ1 differentiated into embryogenic callus, and then a completed plant regeneration,yet hard,green,compact callus was produced only by C312 at the same time. In the field,we initially identified four transgenic cottons by 0.8% basta selection.PCR analysis further confirmed that both CryIIA and Cry9C had been integrated into cotton genome.The result of insect test showed that the both of Bt genes have high resistance to HelicoverPa armigera whose growth and development were significantly suppressed witnin four days.The test also pointed out that different transgenic cottons performed different insecticidal activity,of which A-8-5 had the highest level of resistance.The conclusion:CryIC, CryIIA, Cry9C genes were modified and artificially synthesized by yongjun Lin Professor,with independent intellectual property rights and high insect resistance,which has a very high application value. In practice,genetic engineeringcombinated with traditional breeding methods will be a trend, expecting high yield,high-quality, insect- resistant cotton varieties.