Effect of Priming on Germination and Enzyme Activity of Achillea vermicularis Seeds after Naturally and Accelerated Aging

Ageing induces seed deterioration expressed as the loss of seed vigor and/or viability. Priming treatment, which consists in soaking of seeds in a solution of low water potential, has been shown to reinvigorate aged seeds. An experiment was conducted to evaluate the effects of naturally and accelerated aging on seed germination traits and enzyme activities (proxidase, catalase and superoxid dismutase) in three Achillea vermicularis accessions. Naturally aged seeds were provided from base (stored 10 or15 years at -18 °C) and active (stored 10 or 15 years at 4 °C) cold rooms of Natural Resources Gene Bank of Iran. A two years harvested seeds of the accessions were aged under moisture of 100% and temperature of 40 °C for 48 and 72 hours. The seeds were primed by incubation for 24 hours at 15 °C in solution of polyethylene glycol 6000 (PEG6000) −0.3 Mpa (as osmo-priming), gibberellic acid 250 and 500 ppm (as hormone-priming). Non-primed seeds were used as control. ANOVA suggested significant different among three accessions of A. vermicularis for all germination traits and enzymes activities. Results showed that responses of different accessions to aging and priming treatments were significantly different. The data demonstrated that catalase is a key enzyme for seed repair against ageing ROS-induced damage during priming treatment