Selection of hydroxyproline-resistant cell lines from Solanum Tuberosum L. Callus. II. Plant regeneration and frost tolerance of regenerated plants

The calluses of two hydroxyproline-resistant lines (D20-1 and D30-1) of Solanum tuberosum L. were transferred to a solidified MS medium containing 1.0 mg/I IAA, 2.0 mg/l zeatin, 40.0 mg/l adenine sulphate, 1 g/l casein hydrolysate, 20 g/l sucrose and 10 g/l agar for plant regeneration. The shoot regeneration was only achieved from the callus of line D20–1. Regenerated shoots exhibited morphological variability. The degrees of frost tolerance were higher in the leaves of the regenerated plants compared with the leaves of the non-selected control plants, but lower than that of the callus from which they were regenerated.