Effects Of Chitosan On Nutrient Qualities Of Non-heading Chinese Cabbage(Brassica Campestris Ssp. Chinenis Makino) Dwarf Hybrid No.1 And Regulation Of Chitosan On Nitrogen Metabolism In Its Seedlings

Chitosan was a facultative ion polysaccharide which had special characters such as good bio-compabitility, nontoxicity, easy degrading and so on. Studies showed that chitosan presented regulation on growth and development of root, stem, leaf and flower of plant, and has been applied in agriculture as plant growth regulator more and more in recent years. The main aim of this paper was to lay foundations for further understanding the effects of chitosan on growth and development and qualities of non-heading Chinese cabbage, and to supply some beneficial researches on application of chitosan in agriculture. The effects of chitosan with treating seed ( different concentrations:0.2, 0.4, 0.6, 0.8 and 1 .Omg/g .^and spraying leaf (different concentrations: 5, 10, 20, 40 and 80 u g/ml) on nutrient qualities and agronomic characters of non-heading Chinese cabbage were studied. The results showed that contents of soluble protein ,total amino acid, soluble sugar, Vitamin C and total chlorophyll increased significantly in non-heading Chinese cabbage after being treated with 0.4~0.6mg/g seed and 20~40 u g/ml of chitosan respectively. The content of crude fiber, on the contrary, decreased obviously. Therefore the quality of cabbage was improved. Chitosan also great improved the agronomic characters of non-heading Chinese cabbage, such as whole plant fresh weight, plant height, root length, root fresh weight and the biggest leaf area, and there were certain concentration effects. Meanwhile the optimum concentrations for the greatly improvement were 0.4~0.6mg/g seed for treating seed and 20-40u g/ml for spraying leaf. And it was a more convenient method of treating seed with chitosan solution in practical application.Chitosan had unique regulation effect on nitrogen metabolism of plant, Effects of chitosan on the activities of enzymes relevant to nitrogen metabolism in non-heading Chinese cabbage seedlings were investigated. Non-heading Chinese cabbage seeds and seedlings were treated with 0.6mg/gseedand 20 u g/ml chitosan solution respectively. Theresults indicated that the activities of nitrogen reductase(NR) and glutamate dehydrogenases(GDH) were greatly increased, the endopeptitases(EP) activities and the contents of free amino acid, however, were decreased obviously compared with those of control. All of those showed that chitosan could be plant growth regulator and present certain physiological regulation on nitrogen metabolism in seedlings growth and development of non-heading Chinese cabbage.