EFFICIENT PLANT-REGENERATION FROM CELL-SUSPENSION DERIVED CALLUS OF EAST-INDIAN ROSEWOOD (DALBERGIA LATIFOLIA ROXB.)

A procedure is outlined for the establishment of a proliferating cell suspension culture of East Indian rosewood (Dalbergia latifolia Roxb.) and efficient plant regeneration from callus derived from such cultur es. Callus was induced from hypocotyl segments derived from 1-week-old axenic seedlings on Murashige and Skoog (1962) medium (MS) containing 10.8 mu M naphthaleneacetic acid (NAA) and 2.2 mu M benzyladenine (BA ). Calli were increased by subculturing on MS supplemented with same g rowth regulators and 10% coconut water (CW). Friable calli were used t o initiate cell suspension cultures. Optimum cell proliferation occurr ed in MS containing 10.8 mu M NAA, 2.2 mu M BA and 10% CW, using an in itial inoculum cell density of 2%. Cell clumps composed of 20-25 cells harvested from suspension cultures at the exponential growth phase re adily formed callus within 3 weeks following plating on the semi-solid MS as above. High-frequency shoot-bud differentiation was induced in these calli on MS containing 2.7 mu M NAA and 13.3 mu M BA. The regene ration frequency declined at higher BA concentrations. The organogenic potential of the cell suspensions was influenced by the age of the cu lture. Regenerated shoots were rooted on half-strength MS containing 5 .7 mu M indole-3-acetic acid, 4.9 mu M indole-3-butyric acid and 5.3 m u M indole-3-propionic acid. The plantlets were acclimatized and estab lished in soil.