Seed Dormancy and Germination of Echinochloa oryzicola VASING.: Ethanol as a Dormancy-Breaking Agent

Abstract

Dormancy-breaking efficacy on seeds of Echinochloa oryzicola VASING. was studied with ethanol, the end product of alcohol fermentation, which is endogenously produced in a large amount in non-dormant seeds prior to the redicle protrusion. Primary dormancy of the seeds was markedly broken when dehulled seeds (fruits) were imbibed in 5% (v/v) ethanol solution or exposed to 80% ethanol for 30min. Methanol also showed a dormancy-breaking efficacy, but required higher concentration, among the other alcohols and organic solvents.
No germination was observed when intact seeds (spikelets) were treated with ethanol, probably because of its insufficient penetration, and the intact seeds vacuum infiltrated in 5% ethanol solution showed relatively high germination percentage. No significant difference in rate and amount of water absorption was observed between ethanol-treated and nontreated seeds.