EFFECT OF BIALAPHOS AND PHOSPHINOTHRICIN ON PLANT-REGENERATION FROM LONG-TERM AND SHORT-TERM CALLUS-CULTURES OF GLADIOLUS

Callus was initiated from in vitro-grown plants of Gladiolus cultivars 'Jenny Lee' and 'Florida Flame.' The age of callus used for regenerat ion of plants was either 9 mo. old or 8 yr old from 'Jenny Lee,' and 4 mo. old from 'Florida Flame. Regeneration medium consisted of Murashi ge and Skoog's basal salts medium supplemented with 2.0 mg/l (9.3 mu M ) kinetin. This medium was supplemented with various concentrations of either bialaphos (Meiji Seika, Tokyo, Japan) or phosphinothricin (Hoe chst-Roussell, Frankfurt, Germany). Bialaphos was more effective than phosphinothricin at stimulating plant regeneration. Plants regenerated from 8-yr-old callus of 'Jenny Lee' only when the regeneration medium was supplemented with 0.10 mg/l bialaphos. A bialaphos concentration of 0.01 mg/l stimulated regeneration from 9-mo.-old callus of cultivar 'Jenny Lee' and 4-mo.-old callus of 'Florida Flame'.