SHOOT REGENERATION FROM TISSUE-CULTURED LEAVES OF THE AMERICAN CRANBERRY (VACCINIUM MACROCARPON)

A method for shoot regeneration from leaf explants in two cultivars of cranberry (Vaccinium macrocarpon Ait.) is described. Modified Anderso n's medium supplemented with combinations of thidiazuron (TDZ) with or without 1 mu M NAA (alpha-naphthaleneacetic acid) was used to optimiz e shoot regeneration. The effect of light or dark incubation was also determined. Maximum regeneration was obtained in the light in the pres ence of 10 mu M TDZ and 1 mu M NAA. While this medium was suitable for leaf explants obtained from shoot cultures, regeneration did not occu r from leaves collected from greenhouse-grown plants. Elongation of th e regenerated shoot tips did not occur until explants were transferred to growth regulator-free medium at which time only a minority of shoo ts elongated. Elongated shoots could be dissected away from leaf tissu e, rooted easily, and acclimitized to ambient conditions.