不同生育期遮荫淹水对烤烟形态及抗氧化系统的影响

Effects of shading and waterlogging on morphology and antioxidants of flue-cured tobacco at different growth stages

采用盆栽试验研究了不同生育期遮荫淹水对烤烟形态、抗氧化系统和丙二醛(MDA)含量的影响。结果表明:(1)伸根期处理前期和旺长期处理后烟株株高增加,3个时期处理均使烟株茎围变小、最大叶面积增大,伸根期处理使烟株最大叶长宽比显著增加;(2)各时期处理后烤烟GSH含量均下降,过氧化物酶(POD)活性均升高,伸根期处理后过氧化氢酶(CAT)活性明显增加,而超氧化物歧化酶(SOD)活性则在各个处理间变化较大;(3)3个时期处理后烤烟MDA含量均显著高于对照,而在生育末期均低于对照;(4)相关分析表明,MDA含量与对照POD活性、伸根期处理的CAT活性、成熟期处理后的GSH含量、POD和CAT活性均呈极显著负相关;旺长期处理后MDA含量与POD、CAT和SOD活性呈极显著或显著负相关。

Abstract： Pot experiment was conducted to study effects of shading and walerlogging on antioxidants （content of GSH, activity of SOD, POD and CAT） and malondialdehyde （MDA） content of flue-cured tobacco at different growth stages. Results showed that ： （ 1 ） Plant height increased after shading and waterlogging at early stage of root elongation and vig orous growth stage. Stem girth and maximum leaf area decreased and increased respectively after shading and waterlog ging at every growth stage. Maximum leaf length/width ratio significantly increased in root elongation. （2） Content of GSH under three shading and waterlogging treatments were all lower than control groups. Peroxidase （POD） under shad ing and waterlogging at three growth stages kept higher activity than control group. Catalase （CAT） activity under shad ing and waterlogging at root elongation stage obviously increased. Superoxide dismutase （SOD） activity showed great change among all treatments. （3） After shading and waterlogging at three growth stages, MDA content were either high ly significant or significant than control group, and MDA content of three shading and waterlogging treatments were all lower than control group at the end of growth stage. （4） Correlation analysis showed that MDA content of control group had a highly significant negative correlation with POD activity. MDA content under shading longation stage had a highly significant negative correlation with CAT activity. After shading growth stage, MDA content had significant SOD. After shading and waterlogging at ripe or highly significant negative correlations with and waterlogging at root e and waterlogging at vigorous activity of POD, CAT and stages, MDA content had highly significantly negative correlations with GSHcontent and activity of POD and CAT.