Efficient Agrobacterium-mediated transformation and recovery of transgenic plants from pear

An efficient and reproducible method was established for genetic transformation of one pear variety (Conference) using A, tumefaciens-mediated gene transfer. Wounded leaves of in vitro micropropagated plants were cocultivated with the strain EHA101 with the binary vector pFAJ3000 carrying the chimaeric nptII and gus 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 hybridization, respectively. The transgenic plants could be successfully acclimatized in the glasshouse. This transformation procedure was also successfully applied to two other pear varieties, namely Doyenne du Comice and Passe-Crassane, albeit at lower transformation rates.