High-frequency plant regeneration from seed-derived callus cultures of Kentucky bluegrass (Poa pratensis L.).

Shoot regeneration from seed-derived callus cultures of Kentucky bluegrass (Poa pratensis L.) was tested on MS basal medium supplemented with four different growth regulators. Regeneration frequencies for medium supplemented with 10 μM 2,4-dichlorophenoxyacetic acid (2,4-D), 60 μM 4amino-3, 5,6-picolinic acid (picloram), or 30 μM 3,6dichloro-o-anisic acid (dicamba) ranged from 0.4 to 4%. Medium supplemented with 30 μM dicamba plus 10 μM 6-benzylaminopurine (BA) resulted in regeneration of shoots from 20% of the calli tested. Higher rates of growth regulators (60 or 90 μM dicamba, 20 μM BA) resulted in regeneration of shoots from 45% of calli of the cultivar 'Baron'. In a subsequent study, the response of 12 North American cultivars grown on these media was cultivar-specific, with mean frequencies of regeneration ranging from 4% to 40%.