Comparative analysis of the germination of barley seeds subjected to drying, hydrogen peroxide, or oxidative air plasma treatments

Acceleration in germination time by 12–24 h for barley seeds treated with atmospheric air plasmas may have a significant economic impact on malting processes. In this study, the increase in germination rate and decrease in contamination level upon plasma treatment could not be directly correlated with any significant increase in the water uptake capacity, except for seeds exposed to mild drying treatment. A variety of germination essays have been carried out with seeds impregnated with an abscisic acid solution, a retarding factor of germination, treated with a peroxide solution, and/or subjected to the plasma and drying treatments. Results suggest that plasma and hydrogen peroxide treatments induce the formation of reactive oxygen and nitrogen species that affects the abscisic acid factor and accelerate the germination rate. Air plasma treatment of barley seeds enhances the germination rate even if they are saturated with abscisic acid, an intrinsic germination retardant. Similar to the effects of a hydrogen peroxide treatment, plasma implies the generation of oxygen and nitrogen species without changes in the topography. The hydrophilic behavior induced by the plasma has not had repercussions on the water uptake of the seeds, unlike what happens with a drying treatment.