Direct shoot regeneration from leaf segments of mature plants of Echinacea purpurea (L.) Moench

This is the first communication of direct shoot regeneration from fully developed leaves of potted mature Echinacea purpurea plants. Shoot buds were induced directly on the adaxial surface of mature leaf tissues of E. purpurea 30 d after culture initiation on Woody Plant Medium (WPM) supplemented with various levels of 6-benzyladenine (BA). Maximum shoot organogenesis, with 12-20 shoots per leaf segment, was obtained with 5% coconut milk and 2.5 mg l(-1) (6 muM) BA in 30 d. Callus was induced using 0.5 mg l(-1) (1 muM) alpha-naphthaleneacetic acid and 2.5 mg l(-1) (6 muM) BA. The regenerated shoots were rooted on WPM supplemented with 1.5 mg l(-1) (3 muM) of indole-3-butyric acid, 3% sucrose, and 0.85% agarose. Rooted plants were successfully transferred to soil in pots and appeared morphologically normal and flowered in a growth chamber.