Abstract: In order to explore the effects of nitrogen priming on the oxidation resistance of Bothriochloa ischaemum,seeds of B. ischaemum were primed with different concentrations (0,70,140,280 and 1 120 mmol·L^-1) of ammonium nitrate solution for 0 (CK),3,6,9 and 12 hours,the activities of superoxide dismutase (SOD),glutathione reductase (GR),ascorbate peroxidase (APX) and catalase (CAT),as well as the content of malondialdehyde (MDA) were analyzed. The results showed that the effect of nitrogen priming on antioxidant capacity of B.ischaemum was closely related to the concentration and priming time. The activities of SOD，GR，APX and CAT of B. ischaemum increased first and then decreased with the increase of nitrogen priming concentration,while the content of MDA decreased first and then increased. Low priming concentration of ammonium nitrate (≤140 mmol·L^-1) increased SOD,GR,APX and CAT activities,and decreased MDA content of B. ischaemum. While the high priming concentration (≥280 mmol·L^-1) got an opposite. At the same nitrogen priming concentration,SOD,GR,APX and CAT activities in B. ischaemum were the lowest for 12 h priming,along with the highest MDA content. The priming at concentration of 140 mmol·L^-1 for 6 h was the best treatment to improve the antioxidant performance of B. ischaemum for the highest SOD,GR,APX and CAT activities and the lowest MDA content,which will be conducive to the germination of B. ischaemum.

Key words: Seed priming, Bothriochloa ischaemum, Nitrogen deposition, Seed, Antioxidant ability

摘要： 为了探索白羊草（Bothriochloa ischaemum）种子抗氧化性能对氮引发的响应，试验用不同浓度（0，70，140，280和1 120 mmol·L^-1）的NH₄NO₃溶液引发白羊草种子0（CK），3，6，9，12 h后，分析其超氧化物歧化酶（Superoxide dismutase，SOD）、谷胱甘肽还原酶（Glutathione reductase，GR）、抗坏血酸过氧化物酶（Ascorbate peroxidase，APX）和过氧化氢酶（Catalase，CAT）活性，以及丙二醛（Malondialdehyde，MDA）含量的变化规律。结果表明：氮引发对白羊草种子抗氧化能力的影响与其浓度和引发时间有密切关系；白羊草种子SOD，GR，APX和CAT活性随氮引发浓度的增加先升高后降低，而MDA含量则先降低后升高，低浓度（≤140 mmol·L^-1）的氮引发提高了白羊草种子SOD，GR，APX和CAT活性，并降低了其MDA含量，而高浓度（≥280 mmol·L^-1）则正好相反；氮引发浓度相同时，白羊草种子SOD，GR，APX和CAT活性在引发12 h时最低，而其MDA含量则最高。引发浓度为140 mmol·L^-1的氮引发6 h是提高白羊草种子抗氧化性能的最佳处理，将有利于白羊草种子的萌发。

关键词: 种子引发, 白羊草, 氮沉降, 种子, 抗氧化能力