Tomato Resistance To Cucumber Mosaic Virus Disease Of Genetic Transformation

A procedure for producing transgenic tomato plant resistant to cucumber mosaic virus (CMV) mediated by Agrobacterium Twnefaciens strain LBA4404 carrying a binary vector pR- A ODD, which contains kanamycin-resistance gene and the cucumber mosaic virus replicase gene with ODD deletion, is described. Agrobacterium Tumefaciens strain LBA4404 carrying a binary vector pTOK233 which contains the GUS reporter gene and a kanamycin-resistance gene NPTII was employed for optimizing the transformation system which was evaluated by the GUS( fi -glucuronidase) transient expression. To determine the optimum conditions for Agrobactium infection, cotyledon was used as the explant which had the higher transgenic efficiency and regenerating frequency than hypocotyl. The relative small explant size was superior to the large ones in terms of calli induction. It has also been found that the callus proliferated more when cultured under light than in the dark. The optimum inoculation and co-cultivation durations were 8-10 minutes and 2 days respectively. Furthermore, the infection frequency was generally higher when the co-cultivation medium was at pH 5.0 and the bacterium concentration OD6oo=0.15 was applied. The addition of AS (50 jj mol/L) to the co-cultivation medium increased the infection frequency. Field spray test showed that the transgenic tomato plants were resistant to 100 mg/L Kanamycin well the wild type was not.