Changing law of antioxidant protective enzyme activity about island cotton at different growth stages

The four varieties of island cotton were used as the Experimental materials. The Variations of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbic acid oxidase (AAO) and polyphenol oxidase (PPO) activity were studied at different growth stages. The results showed that five kinds of enzymes had their own variation; also had their own evaluation of the critical period.