The influence of anoxia and ethanol on barley seed death

Abstract

SUMMARYSurvival of deteriorated barley seeds in wet soil was improved by exposure to 70% oxygen compared with that in air and decreased by the imposition of anoxia. Deteriorated seeds were more sensitive to anoxia than non‐deteriorated seeds, the former died within 4 days, while the latter survived more than 7 days.Ethanol accumulated in non‐deteriorated seeds in wet soil conditions during the first 24 h and thereafter declined, while it increased to higher concentrations over 3–4 days in deteriorated seeds. High concentrations of ethanol were recorded in seeds in anaerobic conditions regardless of the level of deterioration.It was concluded that oxygen diffusion to the seeds was severely restricted in wet soil resulting in a switch to anaerobic respiration, the products of which, indicated by ethanol content, accumulated within the tissues. Non‐deteriorated seeds tolerated higher concentrations of ethanol than deteriorated seeds and the coleorhiza extruded through the covering layers more rapidly facilitating gaseous exchange, while in the latter, anaerobic products accumulated to toxic levels.