Somatic Embryogenesis and Plant Regeneration from Suspension Cultures of Timothy ( Phleum pratense L.)

Abstract

Somatic embryogenesis and green plant regeneration of timothy ( Phleum pratense L.) were successfully established using immature inflorescences and seedling stems. The capacity for somatic embryogenesis from immature inflorescences was higher than that from seedling stems. Immature inflorescences of 0.5-1.5 cm in size cultured in Murashige and Skoog (MS) basal medium containing 2 mg l -1 2,4-dichlorophenoxyacetic acid (2,4-D) gave the best performance in callus induction. Suspension cultures were initiated from friable nodule-forming callus in MS basal medium supplemented with 5.0 mg l -1 2,4-D and 0.5 mg l -1 abscisic acid. Fast-growing and finely dispersed suspension cultures were established. Kinetin at 1.0 mg l- 1 and 2,4-D at 0.1 mg l -1 was the best plant growth regulator combination in green plant regeneration from direct callus differentiation and suspension cultures. The highest green plant regeneration was achieved 5-7 weeks after initiation in suspension culture. More than 100 regenerated plants were obtained.