Effects of Different Levels of Nitrogen Application on the Physiological Characteristics of Maize Seedlings under Salt Stress
The effects of different levels of nitrogen application on the growth,biomass,ionic homeostasis,anti-oxidant enzyme activities,total flavonoids and other physiological characteristics of maize seedlings under salt stress were investigated using the maize variety"Hongxing 990"as the material.The results showed that normal nitrogen application(T3)significantly promoted the growth and biomass accumulation of maize seedlings under salt stress.High nitrogen(T4,T5)and low nitrogen(T1,T2)treatments significantly increased the activities of SOD(Superoxide Dismutase),POD(Peroxidase)and CAT(Catalase)in maize leaves under salt stress,but high and low nitrogen treat-ments significantly reduced the content of MDA(Malondialdehyde).Under salt stress,both high and low nitrogen in-creased proline and total flavonoid synthesis,but decreased amino acid and chlorophyll contents.In addition,the contents of Na+,Cl-and K+showed a tendency to increase and then decrease with increasing concentrations of ap-plied nitrogen,whereas NO3-showed the opposite tendency of decreasing and then increasing.Significant correla-tions were found between antioxidant enzyme activities(SOD,CAT,POD)and several physiological indices(proline,total flavonoids,amino acids,chlorophyll,NO3-,Cl-,and K+),such as a significant positive correlation between SOD and proline.Overall,the results of this study provide a theoretical basis for future improvement of salt tolerance in seedling maize by nitrogen application under salt stress.
万方数据
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