Agrobacterium-Mediated transformation of watermelon (Citrullus lanatus (Thunb.) Matsun and Nakai) and plant regeneration

Cotyledon and hypocotyl segments of watermelon (Citrullus lanatus (Thunb.) Matsun and Nakai ) were used for the transformation performed by the EHA101 strain of Agrobacterium tumefaciens harboring the binary vector pGA482GG carrying the marker genes the neomycin phosphotransferase II determining resistance to kanamycin and (3- glucoronidase (GUS). Cotyledon and hypocotyl segments of watermelon plants obtained in vitro conditions were cultivated on MS medium containing different concentrations, combinations of hormones, and the better shoot regeneration medium was observed on MS medium containing 2 mg/1 BAP + 1 mg/1 ABA. The maximum shoot regeneration was obtained from the proximal ends of cotyledon leaves that were cut transversely in to two halves. The best results were observed on the root formation taken by the obtained plants that grow in 0,5 mg/1 IB A MS medium. After 3 weeks later, the plant roots, which reach 10- 12cm heights, were transferred to the soil for adaptation to natural condition, and it was observed that these plants had flower. After determining the appropriate medium and the plant tissues for the transformation, this transformation was done by the Agrobacterium tumefaciens. Plant tissues selected in the MS medium containing kanamycin were tested by histological GUS assays and blue color staining was observed on the tissues. DNA was isolated from transgenic plant tissues and shoots regenerated from these transgenic plants. PCR were done to indicate transferred npt H and GUS genes. As results of the electroforeze of PCR products, 700 bp specific DNA bands of npt II and 660 bp specific DNA bands of GUS were observed. With this study, the regeneration system on watermelon for later studies and the gene transformation system for transforming gene in aspect of the agriculture were formed. Key words: Agrobacterium tumefaciens, (Citrullus lanatus (Thunb.) Matsun and Nakai), Plant Regeneration, Gene Transformation n