Cytokinin Secretion by Frankia sp. HFP ArI3 in Defined Medium

Abstract
Frankia sp. HFPArI3 (host plant Alnus rubra Bong.) was grown in defined medium and the culture solution was analyzed for the presence of various cytokinins and related compounds. N6-(.DELTA.2-isopentenyl) adenosine was the only cytokinin detected by both high performance liquid chromatography and gas chromatography-mass spectrometry, at levels of approximately 1 ng/ml culture medium.