Qualitative characterization of the endogenous cytokinins in red pine and aspects of their influence on seedling development

Abstract

Red pine seedlings alternate between root and shoot production in a periodic fashion. This habit is referred to as episodic growth and is assumed to be con trolled by endogenous plant growth regulators. This project was concerned with the role played by cytokinins in the control of episodic growth. After confirming the existence of episodic growth in red pine seedlings, a car rier solution was optimized and a series of exogenous application trials was con ducted. Only those solutions containing a surfactant and N®-benzylaminopurine (BAP) produced an observable response. Foliar applications of BAP induced the formation of an apical cluster of buds. As the BAP concentration was increased from 2.5 to 200 mg/1, there was a corresponding increase in the number of buds formed. Hypocotyl length and the percentage of the induced buds that elongated