Acta Univ Latv (2004) 676: 247–250

Agrobacterium rhizogenes-mediated transformation and regeneration of bisexual Actinidia kolomikta

Abstract

The aim of the work was to produce Actinidia kolomikta plants with modified growth and root capacity. Four highly branched root clones were obtained from leaf explants of bisexual A. kolomikta plants by Agrobacterium rhizogenes transformation. Two transformed shoot clones were regenerated from hairy roots on solid half-strength Woody Plant Medium with varying concentrations of benzyladenine (0.5 to 5.0 mg l-1). Shoot cultures of transformed plants required culture media for proliferation and rooting different from those suitable for the control. The response to exogenos hormones was modified in the transformants. Shoot proliferation required benzyladenine as the only hormone. Microcuttings from transformed in vitro plants formed dense root systems on auxinfree Murashige and Skoog medium. Leaf explants from transformed plants produced roots on hormone-free Murashige and Skoog medium, a typical response of plants regenerated from hairy roots. No rooting was observed on untransformed actinidia leaf explants under the same conditions. Transformants that had grown in the unheated greenhouse suffered from pests, and they tended to be sensitive to frost in winter.