PRESUMPTIVE TRANSFORMATION OF APPLES BY CO-CULTIVATION WITH AGROBACTERIUM TUMEFACIENS
Presumptive transformed callus and shoots were produced by a leaf disc transformation-regeneration method. Leaf explants excised from in vitro grown shoot cultures of 'Red Delicious' apple (Malus x domestica Borkh.) were co-cultivated with Agrobacterium tumefaciens strain containing either the virulent plasmid C58 or the disarmed plasmid pGV3850::1103neo. After co-cultivation for 36 hours, the leaf pieces were placed on the appropriate selection medium and incubated in the dark at 26°C. On average 10% of the leaf pieces were able to form calli under selection conditions for phytohormone-independent growth, in contrast to controls which did not form calli. Abnormal shoots were formed from about 2% of the C58 transformed calli, while normal shoots were formed from about 1% of the pGV3850::1103neo. The presumptive presence of nopaline-synthase activity in the calli provided evidence of expression of T DNA genes and genetic transformation.
Mooney, P.A. and Goodwin, P.B. (1989). PRESUMPTIVE TRANSFORMATION OF APPLES BY CO-CULTIVATION WITH AGROBACTERIUM TUMEFACIENS. Acta Hortic. 240, 59-62