Effects And Mechanism Of Seed Treatments On Enhancing Sweet Pepper Seed Vigor

Thick seed coat and inclination to seed vigor decrease caused many negative influences to sweet pepper seedling. In order to tackle the problem, several treatments were designed to study the effect of seed treatments and the mechanism of increasing seed vigor, The results were determined as follows:1. PEG,KH₂PO₄,GA3 and low temperature treatments could improve seed vigor of sweet pepper at proper condition, especially GA3 and KH₂PO₄. The best conditions for PEG,KH₂PO₄,GA3 and low temperature treatments were 250 g/l,25℃,48 h;15 g/l,25℃,36 h;300 mg/l,25℃,48 h;0-2℃,72 h , respectively.2. With aging time increasing, seed vigor index and dehydrogenase activity decreased, and reached inflexion at the fifith day. The activity of amylase,protease,lipase,superoxide dismutase,peroxidase,catalase increased , while relative electric conductivity and soluble sugar of seed leakage decreased after treatments. All these indexes were correlated significantly with seed vigor. The correlation between relative electric conductivity of seed extract and seed vigor was lower than that between Soluble sugar leakage of seed and seed vigor. GA3 and PEG could significantly decrease relative electric conductivity of seed extract and soluble sugar leakage of seed, and had the best repairing effects on plasma membrane. PEG treatment had the best effect on amylase, KH₂PO₄ treatment had the best effect on protease, and low temperature had the best effect on lipase. PEG and KH₂PO₄ teratments could obviously increase the activity of antioxidant enzymes and thus decrease lipid peroxidation. Decreasing of lipid peroxidation and improving of nutrient metabolism were two important factors for enhancing seed vigor. Seed treatments had two kinds of repairing effects: physical and biochemical repairing effect and biochemical repairing...