Effects Of Degradated Chitosan By Irradiation On Physiological Traits Of Drought During Wheat Seedling Stage

As a major crop,wheat is planted abroad in the world.The effect of drought to wheat is seriously.Chitosan is a kind of aminoploysaccharides,derived from chitin by deacetylating.In recent years,chitosan has been investigated and used abroad as non-contamination pesticide and growth regulator in agricultural area.This experiment was conducted with drought light-resistant wheat cultivar Wan NO.46 and drought resistant wheat cultivar Hanxuan NO.10,irradiated chitosan with three kinds of dose(50kGy,200kGy,500kGy) acetum was dealt with the wheat seeds and was prayed on the leaves of wheat seedlings respectively,then observed the physiological and biochemical effect of irradiated chitosan on drought resistance of wheat.The results showed that:The three kinds of chitosan solution could improve the germination percentage of seed,moisture percentage of seedling,the dry weight of root,ratio of root to shoot of two kinds of wheat compared with the control,but increased with different degree.Chitosan with 200kGy dose treatment has great effect on the seedling shape character of wheat Wan NO.46 than another two treatments.In addition,chitosan with 50kGy dose treatment has great effect on the seedling shape character of wheat Hanxuan NO.10.The physiological and biochemical indexs of wheat seedlings were measured,the results indicated that:During the whole stage of drought stress,for the wheat Wan NO.46 seedlings treated by chitosan with 200kGy dose and the wheat Hanxuan NO.10 seedlings treated by chitosan with 50kGy,the soluble protein contents and the contents ofchlorophyll were increased remarkably compared with the control(P＜0.05),the contents of malondialdehyde (MDA)were decreased obviously(P＜0.05).The activities of antioxidases such as superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)were increased significantly compared with the control(P＜0.01),which could make the performance period last more than 7 days.This study indicated that irradiated chitosan was capable of improving the ability to eliminate reactive oxygen species,protecting the functions of bio-membrane, raising the physiological synergisms in drought resistance of wheat seedlings.