不同产量水平大豆叶片保护酶活性的比较

【目的】探讨不同产量水平大豆叶片保护酶活性的变化规律，为大豆育种和高产栽培提供生理依据。【方法】选择3个不同产量水平(低产品种、高产品种、中产品种)的9个栽培大豆(Glycine max(L.)Merr.)品种，在相同的环境条件下种植，在大豆结荚期以后，测定大豆叶片超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）活性及叶片丙二醛(MDA)含量和细胞膜透性。【结果】在结荚期后，不同产量水平大豆叶片的SOD、POD、CAT活性表现为高产品种＞中产品种＞低产品种，其活性变化趋势相同，均在鼓粒盛期达到最大，然后下降，高产品种叶片SOD、POD、CAT活性均显著高于低产品种；不同产量水平大豆叶片MDA含量和细胞膜透性则表现为低产品种＞中产品种＞高产品种，随生育进程均呈上升趋势，以成熟期最大，高产品种MDA含量和细胞膜透性极显著低于低产品种。【结论】在结荚期以后，高产大豆品种清除活性氧的能力较强，膜脂过氧化程度较低，叶片衰老延缓，而功能期延长，有利于后期干物质积累,进而有助于提高产量。

Comparison of protective enzyme activity in leaves of soybean at different yield levels

【Objective】The study was performed to explore changes of protective enzyme activities in leaves of soybean at different yield levels.The purpose was to provide some physiological basis for soybean breeding and high-yield cultivation.【Method】Nine soybean(Glycine max(L.) Merr.) cultivars were divided into three yield levels(low yield cultivars,high yield cultivars,middle yield cultivars) were planted under the same environmental condition.After podding stage,the superoxide dismutase(SOD) activities,catalase(CAT) activities,peoxidase(POD) activities,malondialdehyde(MDA) contents and cell membrane permeability were measured in soybean leaves.【Result】After podding stage,the activities of SOD,CAT and POD in leaves were the highest at high yield cultivars,then at middle yield cultivars and the lowest at low yield cultivars.The change tendency of those enzymes was consistent,which all reached maximum value at seedfilling-flourishing stage and then decreased.The activities of SOD,CAT and POD in leaves of high yield cultivars were significantly higher than that of low yield cultivars.The contents of MDA and cell membrane permeability in leaves were the highest at low yield cultivars,then at middle yield cultivars and the lowest at high yield cultivars after podding stage.Following the breeding proceeding,the contents of MDA and cell membrane permeability all showed rising tendency and reached maximum value at maturation stages,then the MDA contents and the cell membrane permeability of high yield cultivars were very significantly lower than those of low yield cultivars.【Conclusion】After podding stage,the ability in leaves of high yield cultivars to eliminate active oxygen was better and the degree of lipid peroxidation was low.The leaf of high yield cultivars senescence was delayed and the function of leaves extended,which make for dry matter accumulation at later stage and conduce to increase yields.