The effects of irradiating gladiolus (Gladiolus x grandiflora hort.) cormels with gamma rays on callus formation, somatic embryogenesis and flower color variations in the regenerated plants

The effects of gamma irradiation to cormel explants on callus formation, so matic embryogenesis, and flower color variations of the regenerated plants were examined in gladiolus (Gladiolus X grandiflora hort.) 'Traveler' and ' Topaz'. The rate of somatic embryogenesis decreased as the exposure dosage was increased. The total dosages of 100-200 Gy at 10 Gy . hr(-1) caused a 5 0 percent reduction in the rate of callus formation and somatic embryogenes is (RD50). The flower color variants occurred in 'Traveler 'but not in 'Top az'. The frequency of flower color variants increased, resulting in the app earance of extremely deep colors and morphological variants when tissue cul ture technique was used in combination with gamma irradiation. Most newer c olor variants were solid (i.e., nonsectorial-chimeric) variants. These resu lts show that the application of tissue culture technique in combination wi th gamma irradiation could lead to a high frequency of variants, diversifyi ng the germplasm pool for breeding of other vegetatively propagated ornamet al plants.