钠替代钾下甜菜体内MDA含量、SOD和CAT活性的差异

选取耐盐性不同的材料在钾钠浓度比为3∶0、1.5∶1.5、0.75∶2.25、0.15∶2.85、0.03∶2.97营养液中培养21d,测定各样品中丙二醛（MDA）含量、超氧化物岐化酶（SOD）和过氧化氢酶（CAT）活性。结果表明,在钾钠比3∶0～0.03∶2.97范围内耐盐性强品种MDA含量均无明显变化;耐盐性弱品种MDA含量在钾钠比0.75∶2.25～0.03∶2.97中随钾钠比降低呈逐渐上升趋势。耐盐性强品种在钾钠比3∶0～0.75∶2.25中SOD活性与钾钠比成反比,在钾钠比0.75∶2.25～0.03∶2.97中SOD活性与钾钠比成正比;耐盐性弱品种在钾钠比3∶0～0.75∶2.25中变化趋势与耐盐性强品种相似,在钾钠比0.75∶2.25～0.03∶2.97中SOD活性变化趋于平稳。在钾钠比3∶0～0.03∶2.97中耐盐性强品种CAT活性无明显变化,酶活性在70U/g mf小幅波动;耐盐性弱品种在钾钠比3∶0～1.5∶1.5中耐盐性弱品种CAT活性无明显变化,且与耐盐性强品种活性相当,在钾钠比1.5∶1.5～0.75∶2.25中CAT活性呈上升趋势,而在钾钠比0.75∶2.25～0.03∶2.97中呈下降趋势。

MDA Content,SOD and CAT Activities of Sugarbeet Cultivated under Different K~＋/Na~＋ Conditions

In this experiment,both of salt tolerant and salt susceptive sugarbeets are cultivated under different K＋/Na＋（3/0,1.5/1.5,0.75/2.25,0.15/2.85,0.03/2.97）nutrient solutions,keeping the invariable K＋ and Na＋ concentration of each solution until the 21st day,and measuring the MDA content,activities of SOD and CAT.Results show that the salt tolerant variety sample＇s MDA content have no apparent diversify.The salt susceptive variety sample＇s MDA content increased gradually from K＋/Na＋ 0.75/2.25 to 0.03/2.97.The SOD activity of the salt tolerant sugarbeet was negatively correlated with K＋/Na＋ in 3/0-0.75/2.25,and positively correlated with K＋/Na＋ in 0.75/2.25-0.03/2.97.The SOD activity of the salt susceptive sugarbeet was similar to salt tolerant sugarbeet in K＋/Na＋ 3/0-0.75/2.25,but little difference in K＋/Na＋ 0.75/2.25-0.03/2.97.The CAT activity of salt tolerant beet is almost the same in K＋/Na＋ 3/0~0.03/2.97;The CAT activity of salt susceptive beet was little difference in K＋/Na＋ 3/0-1.5/1.5,was upward trend in K＋/Na＋ 1.5/1.5-0.75/2.25,and downward trend in K＋/Na＋ 0.75/2.25-0.03/2.97.