渍水胁迫对苗期油菜根系形态与生理活性的影响

盆栽条件下研究连续渍水胁迫对2个油菜品种中双9号和中油杂12号苗期根系形态及生理活性的影响。结果表明，渍水处理初期(前5d)两个油菜品种根系超氧自由基阴离子（O2.-）产生速率均较对照显著提高，超氧化物歧化酶(SOD)活性较对照显著升高，活性氧累积引起的细胞膜脂过氧化程度（MDA含量）变化不显著，根系生物量及形态参数未发生显著变化。但随着渍水时间延长至5d后，根系O2.-产生速率继续加快而SOD和过氧化氢酶（CAT）活性显著降低，细胞膜脂过氧化程度（MDA含量）显著提高；根系组织坏死严重，根生物量显著降低；根系形态发生显著变化，根表面积、根体积、主根长和总根长显著降低，平均根直径显著增加，须根数量明显减少。

Influences of waterlogging stress on roots morphology and physiology for rapeseed

Pot experiment was conducted to investigate the influences of continuous waterlogging stress on roots morphology and physiological activities of rapeseed seedlings(Brassica napus L.cv Zhongshuang 9 and Zhongyouza 12).Results showed that,during the first five days of waterlogging,the rate of superoxide radical(O2·-) production and superoxide dismutase(SOD) activity were both significantly increased.Malondialdehyde(MDA) content caused by O2·-accumulation was not significantly increased,and roots dry weight and morphological parameters had no significant change compared to CK.The rate of O2·-production accelerated 5d after waterlogging,and MDA content increased significantly.SOD and catalase(CAT) activities were significantly decreased,which resulted in significant decrease of roots dry weights and significant changes of roots morphological parameters,including decrease of surface area,volume,total root length and taproot length,significant increase of average root diameter,and significant decrease of the number of fibrous roots.