An evaluation of callus induction and plant regeneration in twenty-®ve turf-type tall fescue (Festuca arundinacea Schreb.) cultivars

In order to investigate the genetic variation in tissue culture response and to ®nd the cultivars with high regeneration ability for genetic transformation, twenty®ve turf-type tall fescue (Festuca arundinacea Schreb.) cultivars, including many elite ones released recently, were evaluated for their callus induction and plant regeneration responses. Callus induction was initiated from mature seeds on a Murashige and Skoog (MS) medium containing 9á0 mg l 2,4-dichlorophenoxyacetic acid (2,4-D). Induced calli were subcultured on the same medium with 2á0 mg l 2,4-D and then transferred to a MS medium supplemented with 2á5 mg l 6-benzylaminopurine (BAP) for plant regeneration. Signi®cant differences were observed among the twenty-®ve cultivars in both callus induction and plant regeneration (P < 0á001). Callus induction rate of viable seeds varied from 4á4% to 51á9%. Callus regeneration rates ranged from 16á7% to 58á8%. Overall regeneration rates (number of regenerated calli over number of cultured viable seeds) ranged from 1% to 22%. Approximately 94% of the regenerants were green plantlets.