Plant transformation using Agrobacterium rhizogenes provides features that, for certain purposes, are advantageous compared to the more commonly used Agrobacterium tumefaciens techniques. In order to obtain transgenic plants after A. tumefaczens mediated transformation with “disarmed” binary vectors, selection of transgenic tissue on antibiotics or herbicides must be possible, and a procedure for regeneration must be worked out (1). In contrast, most plant cells transformed with A. rhizogenes develop into transgenic roots that are easily recognized, separated, and cultivated in vitro (2,3). From these root cultures a number of plants regenerate spontaneously or following hormone application (2–4), and, despite the “hairy root phenotype” (2) of regenerated plants, A. rhizogenes-mediated transformation is useful for recalcitrant species.