不同施肥处理对玉米生育后期叶片保护酶活性及膜脂过氧化作用的影响

Effect of Different Fertilizer Supply of Maize on Protective Enzyme Activities and Lipid Peroxidation of Leaves in Latter Stage

从高产施肥的角度研究了不同氮、磷、钾肥用量对春玉米生育后期叶片保护酶活性与膜脂过氧化产物作用的影响。结果表明:各施肥条件下,各种酶在灌浆期、乳熟期和蜡熟期随玉米生育期的推进呈现出相同的变化趋势,SOD活性先急剧降低,后稍有回升;CAT活性呈下降趋势;POD活性先增后降;MDA含量一直呈上升趋势。不同氮、磷、钾用量对叶片保护酶活性和MDA含量的影响不同,适宜的氮、磷、钾肥用量(N 240kg/hm2、P2O5 150～225kg/hm2和K2O240kg/hm2)可明显提高SOD、CAT活性,降低POD、MDA活性和含量,有效地延缓玉米生育后期叶片的衰老。氮、磷、钾养分缺乏或过量均会使叶片膜脂过氧化程度加剧,较早进入衰老状态。

From the viewpoint of high-yield application of fertilizers, under different fertilizer supply, studies were made about protective enzyme activites and lipid peroxidation of leaves in later stage of maize. Results indicated that at filling stage, milky stage and dough stage, changing of enzymes with growing stage were the same trend, the activities of superoxide dismutase（SOD） reduced sharply then increased slightly; catalase（CAT） declined all the time; peroxedase（POD） increased earlier then reduced, malondialdehyde（MDA） increased straight. Effects of different fertilizer supply on protective enzyme activities and MDA content were different. Propriety N, P, K fertilizer application（N 240 kg/ha, P205 150 - 225 kg/ha and K20 240 kg/ha） can defer decrepitude effectively of leaves at latter growing stage. Apply excessive or lacking N, P and K fertilizer can sharpen lipid peroxidation degree and became decrepitude earlier.