Selection for salt tolerance in tissue culture of sainfoin and recovery of plants from NaCl tolerant callus

Seeds of sainfoin were germinated in MS medium plus 1.2% NaCl to eliminated the salt sensitive seedlings and the hypocotyl segments of survived seedlings were used to induce callus on MS medium containing 1 mg/L 2,4-dichlorophenoxyacetic acid, 0.5 mg/L 6-benzyladenine and 1.2% NaCl. The organigenetic callus tolerating 1.8% NaCl was obtained by continuos selection on NaCl containing medium. Shoots regenerated from the selected callus on MS medium containing 0.2 mg/L alpha-naphthaleneacetic acid and 1 mg/L indole-3-butyric acid. Roots were induced from 3 cm-high shoots on half-strength MS medium plus 2 mg/L alpha-naphthaleneacetic acid or indole-3-butyric acid. The selected tolerant callus and the reinitiated callus from the regenerated plant showed a higher tolerance to osmotic stress than the nonselected callus.