Shoot multiplication and adventitious regeneration in Sorbus aucuparia

Abstract

In vitro mother plants initiated from a mature tree of Sorbus aucuparia, produced numerous propagules on a medium containing 2 μM 6-benzylaminopurine (BAP) and 0.2 μM 1-naphthaleneacetic acid (NAA). These were rooted on a medium containing 0.25 μM NAA and 0.25 μM indole−3-butyric acid. Adventitious shoots were produced on excised leaves and internodes on media containing 10 μM thidiazuron and 0.3–1.0 μM NAA. They formed by direct regeneration in the axils of leaflets of intact leaves. They also developed indirectly, from callus that developed on the rachis of intact leaves, and the cut ends of petioles and internodes. Somatic embryos were produced on cotyledons of zygotic embryos on medium containing 1 μM BAP, 1 μM kinetin, 0.5 μM NAA, 500 mg l⁻¹ casein hydrolysate and 250 mg l⁻¹ glutamine. On basal medium, 69% developed cotyledons and 20% germinated after pre-treatment at 4 °C on medium containing 30 g l⁻¹ maltose.