Somatic embryogenesis and plant regeneration from root sections of Allium schoenoprasum L.

Abstract

A protocol has been developed for somatic embryogenesis and subsequent plant regeneration in Allium schoenoprasum L. Calli were induced from root sections isolated from axenic seedlings and cultivated on media containing either Murashige and Skoog's (MS) or Dunstan and Short's mineral solution supplemented with 5 mu M 2,4-dichlorophenoxyacetic acid (2,4-D) in combination with 6-benzylaminopurine (BA), 6-furfurylaminopurine (Kin) or thidiazuron (TDZ) at 1, 5 or 10 mu M. The highest frequencies of callus induction were achieved on media with 5 mu M 2,4-D in combination with 5 mu M TDZ or 10 mu M BA (78.9% and 78.4%, respectively). Calli were then transferred to 1 mu M 2,4-D, where compact yellow callus turned to segmented yellowish callus with transparent globular somatic embryos at the surface. Calli that were previously grown on media with 5 mu M 2,4-D in combination with 10 mu M BA or 10 mu M TDZ showed the highest frequencies of embryogenic callus formation (45% and 42%) as well as mean number of somatic embryos per regenerating callus. The choice of mineral solution formulation did not significantly affect callus induction or embryogenic callus formation. The embryos could complete development into whole plants on plant growth regulator (PGR)-free medium, but inclusion of Kin (0.5, 2.5 and 5 mu M) in this phase improved somatic embryo development and multiplication. Subsequently transferred to 1/2 MS PGR-free medium, all embryos rooted and the survival rate of the plants in a greenhouse was 96%.