CYTOKININ ACTIVITY OF 4-AMINOPYRIDOPYRIMIDINES TOWARD THE GROWTH OF TOBACCO CALLUS

The cytokinin activity of isoamyl, benzyl and phenyl derivatives of a series of 4-aminopyridopyrimidines and 4-aminoquinazoline was tested o n tobacco callus. Among the derivatives, 2-methyl-4-anilinopyrido[3,4- d]pyrimidine exhibited moderate activity almost comparable to that of kinetin. The position of the nitrogen atom in the pyridine moiety of t he pyridopyrimidine ring mas critical for this activity.