EFFICIENT GENETIC-TRANSFORMATION OF RED RASPBERRY, RUBUS-IDEAUS L

We have developed an efficient transformation system for red raspberry (Rubus ideaus L.) using Agrobacterium mediated gene transfer. Using t his system we have successfully introduced a gene that encodes an enzy me, S-adenosylmethionine hydrolase (SAMase), in raspberry cultivars Me eker (MK), Chilliwack (CH) and Canby (CY). Leaf and petiole explants w ere inoculated with disarmed Agrobacterium tumefaciens strain EHA 105 carrying either of two binary vectors, pAG1452 or pAG1552, encoding ge ne sequences for SAMase under the control of the wound and fruit Speci fic tomato E4 promoter. Primary shoot regenerants on selection medium were chimeral containing both transformed and non-transformed cells. N on-chimeral transgenic clones were developed by iterative culture of p etiole, node and leaf explants, on selection medium, from successive g enerations of shoots derived from the primary regenerants. Percent rec overy of transformants was higher with the selection marker gene hygro mycin phosphotransferase (hpt), than with neomycin phosphotransferase (nptII). Transformation frequencies of 49.6%, 0.9% and 8.1% were obtai ned in cultivars Meeker, Chilliwack and Canby respectively from petiol e explants using hygromycin selection. Genomic integration of transgen es was confirmed by Southern hybridization. Transgenic plants from a t otal of 218 independent transformation events (161 MK, 4 CH, 53 CY) ha ve been successfully established in soil.