Improved flax regeneration from hypocotyls using thidiazuron as a cytokinin source.

The effects of thidiazuron, benzyladenine and zeatin were tested with respect to bud regeneration of different flax explants from hypocotyls, cotyledons and apices of two fibre varieties (Ariane, Viking) and one linseed variety (Antarès). These three cytokinins were tested either alone or in combination with naphthalene acetic acid, indole acetic acid or 2,4-dichlorophenoxyacetic acid.Hypocotyls were the most responsive explants. Thidiazuron was significantly the most effective followed by benzyladenine, and then zeatin, in inducing organogenesis from hypocotyl segments. The optimal thidiazuron concentration for bud regeneration from hypocotyls was 0.1-0.3 μM in combination with 0.01 μM of naphthalene acetic acid. Six days after plating, shoot initials began to appear on hypocotyl sections compared with ten to fifteen days when using benzyladenine or zeatin.