The Effect of 1-Naphthaleneacetic Acid on the Endogenous Cytokinin Content of Aseptically Cultured Bark Segments of Salix babylonica

The formation of an undifferentiated wound callus from the cambialregion of bark explants of Salix babylonica was accompaniedby an increase in the endogenous cytokinin levels of the tissueduring the first six days of culture. Treatment of the explantswith 1-naphthaleneacetic acid decreased the level of extractablecytokinin. This decrease was not accompanied by a reductionin the cell number nor in the growth of the explants as reflectedby changes in dry weight. The significance of these findingsis discussed with reference to the known effects of auxin oncytokinin synthesis and degradation. (Received May 23, 1981; Accepted August 11, 1981)