EfficientAgrobacterium-mediated transformation and recovery of transgenic plants from pear (Pyrus communis L.).

An efficient and reproducible method was established for genetic transformation of one pear variety (Conferénce) usingAgrobacterium tumefaciens-mediated gene transfer. Wounded leaves of in vitro micropropagated plants were cocultivated with the disarmed strain EHA101 harbouring the binary vector pFAJ3000 carrying the chimaericnptII andgus genes. The protocol included a 3-6 month dark period on a regeneration medium solidified with gelrite, which contained 100 mg/l kanamycin. Up to 42% of inoculated leaves produced transformed buds or bud clusters. Expression, presence and integration of transgenes was confirmed by a histochemical test, polymerase chain reaction and Southern blot hybridisation, respectively. The transgenec plants could be successfully acclimatized in the glasshouse. This transformation procedure was also successfully applied to two other pear varieties, namely Doyenné du Cornice and Passe-Crassane, albeit at much lower transformation rates.