Effect of aging on enzymatic and non-enzymatic antioxidant changes and biochemical characteristics in barley (Hordeum vulgare L.) seeds cv. Valfajr

This study was laid out to study the effect of accelerate aging duration onenzymatic and non-enzymatic antioxidant activity and biochemical characteristics of barley (Hordeum vulgare L.) seeds in Islamic Azad University, Boroujerd branch, at 2015 summer, that laid out in completely randomized design with four replications. Treatments included 5 accelerated ageing days (control and 1, 2, 3, 4 and 5 days). Results of analysis of variance showed that effect of ageing on germination percentage, electrical conductivity, soluble sugar, soluble protein,proline, acid ascorbic, catalase, peroxidase and ascorbat peroxidase enzymes were significant. Mean comparison results showed that, increase of ageing duration decreased germination percentage of barley seeds but, Malondialdeid, H2O2 content and electrical conductivity were increased. Soluble sugar and soluble protein were increased until 3 and 2 aging days respectively then decreased. With increasing of aging levels until two days proline content increased then decreased but, ascorbic acid production procedure was decreasing and ascorbic acid production in 1-4 ageing days was more than control. Ageing changed catalase, peroxidase and ascorbat peroxidase amount. With increasing of aging levels until 3 days catalase activity increased and until 2 days peroxidase and ascorbat peroxidase activity were increased then decreased. Lower ageing levels induced enzymatic and non-enzymatic damaging less than higher ageing levels but, with increasing of accelerated ageing until 5 days reactive oxygen species accumulation over come on these antioxidant systems. In this condition seed damage increased that laid to decrease of vigor and seed germination percentage.