Study On Genic Transformation Of Pear Fruit Quality Related PL And Fw2.2 Genes In Micro-Tom Tomato

The firmness and size of pear fruit are important factors affecting the fruit quality. Increasing the fruit edibility and prolonging the shelf life have became the urgent problems to be solved for the production and cultivation of pear. In this research, the stable Micro-Tom tomato regeneration system has been established. By using Agrobacterium mediated method, the PL gene and fw2.2 gene related to the firmness and size of pear fruit were transferred into tomato plant, and through screening and identifying the positive plants, the transgenic tomato plant with integrating the PL gene and fw2.2 gene in pear was obtained, establishing the complete genetic transformation system. Thus, this research laid the foundation for further study on the function of quality gene in pear fruit. The main results are shown below: 1. By comparing the effects of different ways of disinfection and sterilization for explants and the scratch degrees at the back of cotyledons on the induction rates of adventitious buds as well as the effects of the different gradients on the rooting induction, the disinfection method for explants in the regeneration system and the distribution ratio of hormones inducing rooting have been optimized. 2. Based on the efficient regeneration system of tomoto plant, the significant positive correlation was ascertained between the regeneration rate of cotyledons and the concentration of Kan through the comparison and study of how explants affect the selection of Kan resistence and the demination of the sensiblity of Cef, and how the addings of Kan and Cef affect the regeneration rate of cotyledons. In this research, 55 plants with resistance were screened out under the functions of Kan of 40 mg/L and Cef of 300 mg/L; Moreover, through PCR testing, 37 plants were preliminarily identified as PL transgenic plants, the conversion rate was 12.7% and the positive rate was 67.3%. 3. In this research, 300 cotyledons with scratch in the back were inoculated and pre-cultured under the dark treatment for 36 h, subsequently the fw2.2 gene related to the size of pear fruit were transferred using Agrobacterium mediated method; the inoculated cotyledons were immersed in the bacteria liquid for 6min under the condition of OD600=0.4, and dipped and dyed in the dip-dye bacteria liquid with AS of 150 μmol/L and in the differentiation medium with AS of 180 μmol/L after being cultured for totally 60 h. During the process of screening and inducing the adventitious buds resisting Kan, by the way of delaying the selection of Kan, Kan of 25 mg/L and 40 mg/L were respectively added into the differentiation medium and the root media, and 63 screened plants were obtained; through PCR testing, 42 transgenic plants with the fw2.2 gene related to the size of pear fruit were preliminarily identified as PL transgenic plants, the conversion rate was 14.9% and the positive rate was 68.2%.