氮素对不同氮效率小黑麦基因型叶片保护酶活性和膜脂过氧化的影响

Effect of nitrogen on protective enzyme activities and lipid peroxidation in triticale genotypes with different N use efficiency

采用盆栽试验,以氮高效小黑麦基因型(PI429186)和氮低效小黑麦基因型(CIxt74)为材料,设置4个氮素水平0,0.25,0.50,和1.00g N/盆,探讨氮素供应对不同氮效率小黑麦各生育期(苗期、分蘖期、拔节期和最佳刈割时期-抽穗期)植株地上部生物量、叶片保护性酶活性和膜脂过氧化程度的影响。结果表明,1)在同一生育期同一供氮条件下,氮高效小黑麦基因型地上部生物量显著高于氮低效基因型。在同一生育期,小黑麦地上部生物量随供氮量的增加而增大,氮高效小黑麦基因型增加幅度大于氮低效基因型。2)氮高效小黑麦基因型的超氧化物歧化酶(superxoide dismutase,SOD)、过氧化物酶(peroxidase,POD)、过氧化氢酶(catalase,CAT)活性随生育期表现出在同一供氮条件下强于氮低效基因型的趋势,而膜脂过氧化产物丙二醛(malondialdehyde,MDA)含量显著低于氮低效基因型小黑麦。3)相关分析表明,小黑麦地上部生物量与SOD、POD、CAT活性的相关性因生育期不同其相关程度不一;地上部生物量与MDA含量呈负相关关系。这表明氮高效小黑麦基因型叶片保护酶在各生育期通过协同作用,共同起到阻止高浓度氧积累和膜脂过氧化,提高其光合性能,达到增产目的。

To elucidate the effect of nitrogen on biomass of shoot,protective enzyme activities and lipid peroxidation in triticale leaves at different growing stages（seeding,tillering,jointing and heading）,a pot experiment was carried out using four N levels（0,0.25,0.50 and 1.00 g N/pot） with two triticale genotypes,one of high N use efficiency（P1429186） and one of low N use efficiency（Clxt74）.1） At the same N levels,shoot biomass of P1429186 was significantly greater than that of Clxt74 at different growth stages.At the same growth stages,shoot biomass was greater when more N was supplied,and the increasing capacity of P1429186 was much greater than that of Clxt74.2） During seeding,the activities of superxoide dismutase（SOD）,peroxidase（POD）,and catalase（CAT） in leaves of P1429186 were greater than in Clxt74 at the same N levels.Contrarily,malondialdehyde（MDA） content was significantly lower in P1429186 than in Clxt74.3） Correlation analysis showed that shoot biomass had various correlations with the activities of SOD,POD,and CAT in leaves of triticale at different growth stages,and had a negative correlation with MDA content.This indicated that,the protective enzymes of P1429186 can cooperate with each other to eliminate reactive oxygen species,thereby inhibiting membrane lipid peroxidation to increase photosynthesis and yield.