Screening Of The Mutations Induced By The Transposon Activation Construct In Land Cotton

With the development of the transgenic technology mediated by Agrobacterium tumefaciens, the method that establish a mutation bank by DNA insertion is used extensively. The transposon insertional mutation has been one of the approachs for functional genomics study. The materials in this research had been inserted by Ac/Ds transposon activation construct, which is the first time to use this kind of construct in land cotton. We expect to obtain some "dominant" mutations, and offer a mutation bank for cotton functional genomics. The major results obtained in this research are as follows:1. The positive results of amplification with NPTⅡprimer: In T1 plants, the positive rate of transplants of 4105 was 69.8% and was 70.7% of 1107, there were only one percent difference between them, and the efficiency of transformation were almost the same. In T2 plants, the positive rate of transplants of 4105 was 26.0% and was 43.3% of 1107. Positive rates of the two materials in plant T2 were lower than in T1 plants, and the positive rate of transplants of 1107 was higher than that of 4105. So we could suggest that 1107 was more available than 4105 for transformation. Among the 14 lines of plot E in T2 generation, the frequency of the positive results from PCR amplification with Bar gene primer was mainly distributed within 0%～77.8%. We screened 46 transplants only amplified by Bar gene primer, which probably inserted only by Ds element.2. Morphological mutants appeared in 41 strains within 84 strains in T1 generation. These mutants included plant height (higher or lower), leaf type (wider or smaller), leaf color (dark green or pale green), boll (bigger or smaller) and so on. We also made an analysis of some mutants such as plant height, first fruit branch height, fruit branch amount, boll amount per plant. It showed that the diversity reached the level of extremely significance.3. Between 13th to 31th in July, 2006, the anthesis stage of cotton, we made a investigation on the variation amounts of petals in plot E of T2 generation. We found 372 flowers mutated in transplants of 1107 and 95 in transplants of 4105, respectively, among the number of 467 mutated flowers. Obviously, 1107 was suitable for screening the mutations of floral organ. We also found that most of the mutated flowers mainly appeared between 21th to 23th in July, it might be influenced by the day temperature.4. In the research, many mutated plants were screened out in T2 generation. Such as mutations of the boll shape, the plant types, the fruit branch, the golden anther, and so on. They were valuable to further research for cotton breeding.