In this work, 10 sunflower ( Helianthus annuus L.) genotypes were evaluated for their suitability for Agrobacterium tumefaciens-mediated gene transfer based on detection of a reported gene expression (GUS). A number of factors including the type of shoot-tip explant (split vs. intact), bacterial strain/binary vector combinations and wounding intact shoot-tips by particle bombardment were examined. Genotypes showed significant differences in their transformation efficiencies ranging from 0.0 to 82.7% GUS positive explants, hybrid genotypes being more responsive to Agrobacterium infection than inbred lines. Use of split shoot-tip explants did not increase the transformation efficiency over intact explants but the AGL-1/pKIWI strain/vector combination was more effective than the LBA4404/pTOK233 combination. Wounding explants by particle bombardment prior to inoculations with Agrobacterium had no positive effect on transformation.

In this work, 10 sunflower ( Helianthus annuus L.) genotypes were evaluated for their suitability for Agrobacterium tumefaciens-mediated gene transfer based on detection of a reported gene expression (GUS). A number of factors including the type of shoot-tip explant (split vs. intact), bacterial strain/binary vector combinations and wounding intact shoot-tips by particle bombardment were examined. Genotypes showed significant differences in their transformation efficiencies ranging from 0.0 to 82.7% GUS positive explants, hybrid genotypes being more responsive to Agrobacterium infection than inbred lines. Use of split shoot-tip explants did not increase the transformation efficiency over intact explants but the AGL-1/pKIWI strain/vector combination was more effective than the LBA4404/pTOK233 combination. Wounding explants by particle bombardment prior to inoculations with Agrobacterium had no positive effect on transformation.