Changes in endogenous cytokinin-like substances in onion bulbs (Allium cepa L.) cv. Sochaczewska during storage

Abstract

Onion bulbs cv. Sochaczewska were dried under an umbrella roof until October 15th or November 15th and thereafter stored in a cold room at 0-1°C until May 15th. During 4 years of the experiment, the activity of cytokinin-like substances was determined each month during storage. The cytokinin activity showed two to three peaks: at the beginning of storage, in January-February (in one year in December) and at the end of the storage period. No clear correlation was found between cytokinin activity and bulb rooting or sprouting. The length of the drying period occasionally influenced the height of cytokinin activity peaks and displaced the moment of their appearance. Weather conditions in particular years seem to be the main factor influencing the changes in cytokinin activity.