Effect of osmopriming on antioxidant activity of Bersim clover (Trifolium alexandrinum L.)

Abstract

Rapid and uniform seed germination and stand establishment are critical factors of crop production under any condition. Seed priming has been known as one of the most effective seed enhancement techniques to improve germination under unfavorable conditions. Antioxidants are critical factors for vigorous seed germination. Seeds with higher antioxidant profiles are more tolerant to unsuitable conditions than other seeds. A laboratory study was conducted to evaluate the influence of the seed priming technique on seed performance during germination and on antioxidant activity of Bersim clover seeds, an economically important forage crop. Seeds were osmoprimed using solutions of polyethylene glycol-6000 (PEG-6000) giving osmotic potentials of -0.8, -1,-1.2,-1.4 and -1.6, MPa for two priming periods (8 and 16 h). Then best priming treatments were further assessed by measurements of antioxidant enzyme activities. The general finding is that seed priming improved final germination percentage, germination rate, seedling length and vigor indexes. Maximum invigoration was observed in seeds osmoprimed at -0.8 MPa for 16 h. Antioxidant enzyme activities (superoxide dismutase, catalase, and peroxidase) in treated seeds of Bersim clover were significantly increased compared to those in control untreated seeds.

Key words: seed, priming, germination, vigor and antioxidant.