Expression and inheritance of inserted markers in binary vector carrying Agrobacterium rhizogenes-transformed potato (Solanum tuberosum L.)

Transgenic shoots were regenerated from eight
diploid potato hairy root clones obtained by transformation with Agrobacterium rhizogenes harboring next to its
wild-type Ri-plasmid a binary vector containing the
neomycin phosphotransferase and the fl-glucuronidase
genes. The plants exhibited the typical hairy root phenotype. Of the plants isolated, 58% were tetraploid and
38 % were diploid. Flowering and tuberization was much
better in the diploid than in the tetraploid plants. Transgenic plants formed a significantly larger root system
when grown on kanamycin-containing medium as compared to growth on kanamycin-free medium. Direct evidence for genetic transformation was obtained by opine,
neomycin phosphotransferase and fl-glucuronidase assays, and by molecular hybridization. Fourteen flowering diploid plants were reciprocally crossed with untransformed S. tuberosum plants, but only six were successful.
Seedlings obtained from four crosses showed that all
traits were transmitted to the offspring. Molecular analysis confirmed the presence of multiple integrations
(copies) of both vector T-DNA and Ri-T-DNA. The
genetic data, furthermore, suggest that the traits derived
from Ri-T-DNA and binary vector T-DNA are linked,
as no recombination between the different traits was observed.