GENETIC-TRANSFORMATION OF POPULUS-DELTOIDES AND PX EURAMERICANA CLONES USING AGROBACTERIUM-TUMEFACIENS

The susceptibility of different Populus euramericana (Neva, PE68-022 x P. nigra, 71-060 x P. nigra) and P. deltoides (PE68-022 x P. deltoide s) crones to wild-type Agrobacterium tumefaciens strains (A281 and 82. 139) was evaluated in an inoculation experiment, and differences in th e frequency of tumor formation (0-48%) were found. Co-cultivation expe riments demonstrated high transformation ability of oncogenic binary A . tumefaciens strains as compared to disarmed strains. Using oncogenic binary strains, transgenic calluses were obtained from all tested clo nes. The presence of acetosyringone did not influence the transformati on frequency of the disarmed strains. Co-inoculation experiments were performed using leaf discs and a bacterial suspension containing both wild-type and disarmed strains. No positive effects on transformation efficiency were noticed in these conditions either. The transformation of tumors and kanamycin resistant calluses was confirmed by DNA analy sis.