Insect-Resistant Identification Of Bt(Cry1Ab/Cry1Ac) Cotton And Genetic Transformation Of New Bt(Cry1C*) Insect-Resistant In Cotton

According to the statistics of International Service for the Acquisition of Agri-biotech Applications?ISAAA?,there are accumulative totally 20 billion hectares of genetically modified?GM?crops were planted from 1996 to 2015,including 3 million hectares of transgenic cotton.It is obverious to see the benefits of genetically modified crops to farmers and consumers.As the application and promotion of the transgenic Bt cotton significantly reduced the Helicoverpa armigera's effect on cotton production,it was found that there were some problems.On the one hand,it is widely used in cotton breeding that non-transgenic cotton crossed with transgenic cotton which obtain the transgenic application security certificate.The quantitative levels of Bt differed among the different varieties.Last not the least is that insect-resistant genes are single,the existing insect-resistant genes are mainly for the control of Helicoverpa armigera and Pectinophora gossypiella so that other cotton pests such as Spodoptera exigua,Pyrausta nubilalis and other hazards were gradually increased.In 2001,Spodoptera exigua was included in the list of potential outbreaks of important pests in cotton.This study was designed to explore the expression and inheritance of Bt?Cry1Ab/Cry1Ac?gene in cotton,and provide the theoretical basis for insect-resistant cotton breeding.The difference of Cry1Ab/Cry1 Ac protein expression in different cotton varieties,F₁ hybrids of different cotton varieties with different genetic backgrounds and F₁ hybrids of different growth period cotton varieties were determined.The Cry1C* gene was transferred to cotton to study its control of cotton pests and to ensure the healthy development of cotton.The main conclusions are as follows:1)The content of Cry1Ab/Cry1 Ac protein in six different resistant cotton varieties and1)The content of Cry1Ab/Cry1 Ac protein in six different resistant cotton varieties and bioassay of cotton bollworm larvae were determined in two years.The tesult shows that,there was significant different in the content of Cry1Ab/Cry1 Ac protein and bioassay of cotton bollworm larvae between different varieties.The toxic protein content and insect resistance of Gang 383 and Lu 6269 were better than those of other varieties.The toxic protein content and insect resistance of Gang 383 and Lu 6269 were better than those of other varieties.2)There was no significant difference in Cry1Ab/Cry1 Ac protein content among F₁ hybrids of different genetic backgrounds,but the F₁ hybrids were significantly lower than that of the parental.The second and third generation bollworm corrected nortality had significant difference between different genetic backgrounds materials,the genetic background of cotton may have effect on insect resistance.3)There was no signigicant difference in Cry1Ab/Cry1 Ac protein content among F₁ hybrids of different grouth period,but the F₁ hybrids were significantly lower than that of the parental.There was no significant correlation between cotton ripening and Cry1 Ab / Cry1 Ac protein content,also the corrected mortality of Helicoverpa armigera larvae,and it showed that the ripening of cotton had no significant effect on the insect resistance4)2 transgenic Cry1C* T₀ cotton plants were obtained?which can obtain seed?,the follow-up work of differentiation continues.From the 22 T₁ plants,we screening for three plants,which have high Cry1 C protein content and insect resistant well.Include Cry1C*-5-7,Cry1C*-5-8 and Cry1C*-5-14.