A NEW APPROACH TO EVALUATE FIRE BLIGHT RESISTANCE IN VITRO
Apple plants were evaluated for fire blight resistance with an in vitro approach using Erwinia amylovora strain Ea 1/79 carrying plasmid pfdC1Z-gfp. Detached leaves from proliferating shoot cultures were inoculated with a needle dipped into bacterial suspension and subcultured in multi-well plates. After five days of incubation, the leaves were examined with a fluorescent microscope to study invasion of the pathogen into the plant tissue. Standards with known properties were the fire blight resistant type Malus robusta and rootstock M7. As susceptible genotypes the rootstock M26 cv. 'Golden Delicious' and cv. 'Pinova' were used. These genotypes responded in the assay with the expected size of the fluorescent zone. The investigations were also performed with leaves from transgenic apple lines expressing the EPS-depolymerase gene of a bacteriophage to select lines with increased pathogen resistance.
Hanke, V. and Geider, K. (2002). A NEW APPROACH TO EVALUATE FIRE BLIGHT RESISTANCE IN VITRO. Acta Hortic. 590, 397-399
Agrobacterium tumefaciens, Erwinia amylovora, genetic engineering, Green Fluorescent Protein