EFFICIENT AGROBACTERIUM-MEDIATED TRANSFORMATION AND RECOVERY OF TRANSGENIC PLANTS FROM PEAR (PYRUS-COMMUNIS L)

An efficient and reproducible method was established for genetic trans formation of one pear variety (Conference) using Agrobacterium tumefac iens-mediated gene transfer. Wounded leaves of in vitro micropropagate d plants were cocultivated with the disarmed strain EHA101 harbouring the binary vector pFAJ3000 carrying the chimaeric nptII and gus genes. The protocol included a 3-6 month dark period on a regeneration mediu m solidified with gelrite, which contained 100 mg/l kanamycin. Up to 4 2% of inoculated leaves produced transformed buds or bud clusters. Exp ression, presence and integration of transgenes was confirmed by a his tochemical test, polymerase chain reaction and Southern blot hybridisa tion, respectively. The transgenic plants could be successfully acclim atized in the glasshouse. This transformation procedure was also succe ssfully applied to two other pear varieties, namely Doyenne du Comice and Passe-Crassane, albeit at much lower transformation rates.