Highly efficient embryogenesis and plant regeneration of tall fescue (Festuca arundinacea Schreb.) from mature seed-derived calli

We report a protocol for efficient plant regeneration of four tall fescue (Festuca arundinacea Schreb.) cultivars ('Surpro', 'Coronado', 'Summer Lawn,' and 'Fawn') via somatic embryogenesis. Calli were initiated from mature seeds grown on modified Murashige and Skoog (MMS) medium supplemented with 7.0 mg l(-1) (31.7 mu M) 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.05 mg l(-1) (0.23 mu M) kinetin (Kin). Calli were maintained and proliferated by subculture at monthly intervals on MMS medium containing 4.5 mg l(-1) (20.4 mu M) 2,4-D and 0.2 mg l(-1) (0.9 mu M) Kin. Somatic embryos (SE) were induced from seed-derived calli on SE-induction medium (MMS supplemented with 2.0 mg l(-1) 2,4-D and 0.2 mg l(-1) Kin). Plantlets were regenerated from somatic embryogenic calli grown on modified SH medium supplemented with 2 mg l(-1) Kin. Using this optimized protocol, 78.6-82.3% of mature seeds of all four cultivars produced SE clusters, of which 93.5-95.3% regenerated into plants within 10 wk. The regenerants showed no phenotypic abnormalities.