The Transformation System in Foxglove (Digitalis purpurea L.) Using Agrobacterium rhizogenes and Traits of the Regenerants

抄録

Our final goal is to breed dwarf cultivars of foxglove (Digitalis purpurea L.) using Agrobacterium rhizogenes. For this aim, we examined an effective method for hairy root induction, the phytohormone condition for regeneration from the root and traits of the regenerants. In the case of using a filter paper soaked with 1/2MS liquid medium for co-cultivation of leaf pieces with the bacteria, 30-40 hairy roots per 100 pieces were expected to be induced. Higher effect was given for regeneration from the hairy root through callus in zeatin addition than with BA, kinetin and no phytohormone added. In potted plants, numerical values of plant height, number of leaves, spike length, number of florets and leaf size were lower in a strain of transformants than in non-transformants, and both types of the plants exhibited similar plant forms and leaf morphologies. These traits provide novel possibilities for the breeding of dwarf cultivars of foxglove.