Callus and shoot formation in organ and tissue cultures of Hedera helix L., English ivy.

Whole embryos and organs excised from ungerminated embryos and from seedlings of H. helix were cultured to assess their capacity to form callus and regenerate organs. There is a high potential for shoot formation in the explanted cotyledons and in the explanted hypocotyl of the ungerminated embryo. Whole embryos and explanted organs from seedlings produced callus rather than organized structures. In contrast to the excised embryo organs, embryo-derived callus had very low organogenetic potential.