不同氮源处理对高温胁迫下高羊茅抗氧化酶活性的影响研究

he effects of different nitrogen forms(NO3--N、NH4+-N、NH4NO3-N) on the lipid peroxidation and antioxidative defense system in leaves of Festuca arundinacea under high Temperature (38/30℃) were studied by pot experiment. Results indicated that under high temperature: (1) MDA content in leaves of both NO3--N and NH4+-N treated plants increased constantly , reflecting that membrane liquid peroxidation aggravated. While, under the same stress condition, MDA content in leaves of NH4+-N treated plants increased more significantly than those of NO3--N treated ones , however, MDA content in leaves of NH4NO3-N treated plants declined slightly in the first two days and then increased , and the content of MDA is highest among three nitrogen treated plants ; (2)Activity of cell defense enzymes SOD , POD and APX in leaves of NO3--N、NH4+-N and NH4NO3-N treated plants all increased firstly and then decreased, with the increasing of stress time, APX activity all decreased by different extent in three nitrogen treated plants; (3）Under the same stress condition, The activity of SOD, POD, CAT and APX were highest in leaves of NH4NO3-N treated plants . The above results indicated that in present experimental condition, NH4NO3-N treated plants suffered the lowest oxidation stress, which suggested that the treatment with NH4NO3-N was the best practice to significantly increase heat-resistance and postpone the senescence of Festuca arundinacea in summer.