Somatic Embryogenesis from Cultured Cormel Stem Tips and Flower Color Variations among Regenerated Plants of Gladiolus

Abstract

Somatic embryogenesis from the stem tips of cormels resulted in flower color variations among regenerated plants from three Gladiolus cultivars. The highest frequency (51.1%) of somatic embryos was induced in MS medium supplemented with 5mg·liter^-1 NAA. Varietal differences in the somatic embryogenesis occurred ; 'Topaz' and 'Traveler' formed more somatic embryos than did 'Hector'. Flower color variants originated among regenerated plants grown in the field. No chimeric change occured in the floret and in the flower, i.e. all florets of a given plant displayed one color. The frequency of flower color variation differed among the cultivars. The variations were induced in 'Traveler' and 'Hector', but not in 'Topaz'. The flower color of variants changed into pale to deep color from that of original cultivar. Variants were generally smaller in stature with a little shorter spike ; they had fewer, small florets compared with the original cultivar, 'Traveler'. The flower color of few variants reverted to the original cultivar when the plants were propagated vegetatively. These findings reveal that some variations in flower color induced through somatic embryogenesis are useful in developing new Gladiolus cultivars.