Thidiazuron- and Zeatin-induced High-frequency Shoot Regeneration from Leaf and Shoot-tip Explants of Strawberry

Strawberry (Fragaria x ananassa cv. Camarosa) was evaluated to determine a high-frequency shoot regeneration response for leaf and shoot-tip explants. For direct organogenesis from strawberry leaves, combinations of moderate concentrations of thidiazuron [TDZ (0, 2, and 4 mu M)] and 6-benzylaminopurine [BAP (0, 4, and 9 mu M)] added into medium containing Murashige and Skoog (MS) basal salts were compared. The most shoots regenerated per leaf explant were observed with 4-mu M TDZ. Regeneration from shoot tips was evaluated with 0-, 2-, 4-, 8-, and 16-mu M zeatin, ldnetin, or 6-alpha,alpha-dimethylallylamino purine (2ip) tested individually. Optimum shoot proliferation was achieved from shoot-tip explants on medium containing 4-mu M zeatin. Rooting was best without cytokinins in the medium; however, adequate rooting was obtained on the 4-mu M zeatin treatment as well.