Study On The Influence Factors Of Transformation For Colour Cotton Via Agrobacterium Tumefaciens

Cotton is one of the most important nature sources of fiber and oil. With the development of the people's life and focus on the environmental protection, there is a great need of colour cotton. However, the low quality and limited colour hinder the development of the nature source. Traditional way is difficult in increasing the quality of nature-coloured cotton. Plant genetic engineer provides a modern and effective method in solving the problem. Improving the fiber quality of the colour cotton via molecular technique is becoming the hot topic in the world.In this study, we transfer Expansion gene into the green colour cotton apex meristem utilizing Agrobacterium-mediated transformation in order to improve the cotton fiber quality. A system of cotton's transformation for foreign genes and the high efficient tissue culture systerm was primarily established.The main results were listed as follow:PCR analysis showed that plasmid PBinEXN was succeeded in transferring into the E.coli DH5 a and agrobacterium strain EHA105, which can be used for the plant transformation.In order to regenerate plants from the meristem, different phenotype cotton's shoot apex were placed on the MS medium containing different concentration of hormone KT. The results showed that MS containing O.lmg/L KT is the favorite medium for apex to germing and regeneration. This method can greatly shorten the time of plant regeneration and without the limit of phenotype. However increasingthe concentration of hormone , the explants' growth was hindered.In order to establish an Agrobacterium -mediated transformation system of cotton, we invested several main factors influencing transformation efficiency. Green cotton is more sensitive than the other cottons to Kanamycin. We choose 70mg/L as the .selected pressure in our research. The concentration of the agrobacterium liquid greatly influenced the rate of the resistant plantlet, and value of ODeoo with 0.5 in the concentration of the agrobacterium liquid is more efficient used for infection. Physiological state is another key factor. Cotton shoot apexes from 3 days old seedling was used as the recipient with higher rate of resistant plantlet, which is different from other conclusions.In this paper, we researched the influence of vacuum infiltration to the Agrobacterium -mediated transformation system and found the favorite condition, we also discussed the reason of chimera and provided the practicable strategy.There were no reports about transformation of the Expansin gene by vacuum infiltration with Agrobacterium-mediated transformation in colour cotton in previous studies. The method in the study can be reference for other researchers.