The effect of genotype, growth regulators and preconditioning of donor plants on callus induction in anther culture of flax was investigated. Anthers were cultured on modified MS medium supplemented with five different combinations of plant growth regulators. The results suggested that specific combinations of growth regulators must be designed for each genotype. Major differences between the present results and previous reports are discussed. The influence of sucrose concentration was also investigated. For flax cultivar, 'Mikael', callus induction was higher in medium supplemented with 1 mg l(-1) BAP and 2 mg l(-1) 2,4D containing 6% sucrose, while this combination of growth regulators significantly increased callogenesis in cultivars 'Lirina', 'Barbara' and 'Szaphir' when supplemented with 9% or 12% sucrose. The preconditioning of donor plants influenced callogenesis in subsequently isolated anthers. Anthers from donor plants grown at a lower temperature (18/14 degrees C) significantly increased callus induction over those from plants grown at a higher temperature (22/18 degrees C), although each genotype still required optimization of growth regulator combinations in the induction medium. Only 'Mikael' regenerated shoots when the callus was from induction medium supplemented with 2 mg I(-1) BAP and 1 mg l(-1) NAA.