| In 2001, insect-resistant transgenic cotton were grew in 1.6 million ha, and it was about 40% of the planting area of Chinese cotton, but they were almost Bt transgenic cotton. Studies showed bollworm possibly produced some resistance to Bt transgenic cotton after massive planting. Therefore, it was very important of the introduction the synthesized double-gene, GFM CryIA gene and modified CpTI gene, to the elite cotton (G. hirsutum L.) and the production of new style resources of insect-resistance were obtained, cultivation of new style insect-resistant transgenic cotton and rules of inheritance and their insect-resistance and main characters related to physiology and biochemistry were studied.Insect-resistant transgenic cotton plants harbouring double-gene were obtained by the pollen-tube pathway transformation system and the agrobacterium tumefaciens-mediated transformation system. Their selection and identification, studies on space-time expression of the target-gene, influences from adversities, molecular analysis, etc. were proceeded by kanamycin selection, ELISA detection, bio-identification, PCR amplification, Southern Blotting; their inheritance rules was resulted from the separation results of their offspring, their physiological and biochemical characters was studied by activities of enzymes, contents of endogenous hormones, the trends of contents variations of MDA, proline, chlorophyll ,etc.Based on my previous works, the techniques of the pollen tube pathway transformation system and agrobacterium tumefaciens-mediated transformation system were improved, main parameters of technical were optimized, the genotypes of the cotton acceptors were widen, a highefficiency of transformation was achieved, a technical system of transformation on a large-scale was established and a lot of transgenic cotton plants harboring double-gene were acquired. In my experiment, I studied the separation results of the insect-resistance to bollworm of part of the transgenic cotton plants, analyzed and compared their insect-resistance at different growth stages and their insect-resistance of different organs at same growth stages, analyzed and compared the sensitivities of bollworm of different instar of larvae, sensitivities of different generationsbollworms to the transgenic cotton. Leaves. Imitated some special and variable characters of climate and condition of environment, I studied the influences of variations of temperature and the treatments by drought and NaCl, etc to the transgenic cottons. I Studied the activities of SOD, CAT, POD and the trends of contents variations of MDA, proline and chlorophyll and endogenous ABA,IAA of the transgenic cottons.The results showed the surviving rates of the regeneration transgenic plants of different varieties exceed 90% by grafting. PCR and Southern blotting detection results showed the existence of the target gene and indicated the Bt and CpTI genes were inserted into cotton genome. The results of inheritance indicated a lot of transgenic cottons harboring double-gene by the pollen tube pathway transformation did not fit to Mendel Rules that resulted from many copies of insert-gene in the transgenic cotton plants. Same as Bt transgenic cotton, the space-time expression of insect-resistance of the transgenic cotton harboring double-gene to bollworm was different in different times and organs, their insect-resistance had a descending trend during 3rd generation, and afterward, it began to rise during 4rd generation, but the descending extent of the transgenic cottons was less than that of Bt transgenic cotton, the stability of their insect-resistance to bollworm was more than that of Bt transgenic cotton. In the middle-last days of growth, the insect-resistances of the flowers and buds of the transgenic cottons were more than that of its leaves. The research results showed the insect-resistance of the transgenic cottons did not affected by the changes of temperature in the process of growth, and sudden-variations of environment did not influenced the expression...
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