Effect of Chrysanthemum Plant Extract on Flower Initiation in Short‐Day Plants

An extract was prepared from Chrysanthemum plants in flower. It was separated into eight different fractions putting emphasis on the sterol components of the extracts. Fractions 5 and 6 were found to contain active substance (s), which to some extent, brought about floral bud initiation in both Chrysanthemum and Xanthium. The active substance (s) present in the above two fractions might be a sterol (s), similar to those of sitosterol and stigmasterol or other related compounds. Gibberellic acid brought about stem elongation as usual, but was found ineffective in causing any tissue differentiation in both Chrysanthemum and Xanthium. Investigations are underway to separate and identify the different compounds present in fractions 5 and 6. The effects of these compounds on test plants, both individually and in combinations, might provide some valuable information as to the nature of the flowering hormone.