萘对松前水稻(Oryza sativa cv.Matsumae)生长和生理的影响及其残留

The Effect of Naphthalene on Growth and Physiology of Oryza sativa cv. Matsumae and Residues of Nap

以松前水稻为试验材料,研究了5种浓度萘污染土壤对松前水稻生长和生理生化指标的影响,以及植物成熟期时土壤中萘的残留。结果表明:①萘浓度低于20mg·kg-1时促进幼苗茎径、茎长、株高的生长,高浓度对其生长有显著的抑制作用。②萘胁迫对水稻叶片游离脯氨酸和蛋白质代谢均有一定的影响,且影响程度以苗期最为明显,其次是分蘖期和拔节期;水稻幼苗阶段萘的高浓度组MDA累积量极显著高于对照,水稻幼苗阶段受到膜脂过氧化影响较为显著,分蘖期次之;拔节期水稻开始新生器官,抗性较弱,萘胁迫产生的过氧化作用超过了水稻的承受范围,使SOD活性显著降低。③在试验所设萘浓度范围内,水稻各生长期叶片叶绿素和光合作用速率均呈不同的变化趋势,但是变化幅度均不超过对照的±5%,说明萘胁迫对松前水稻的光合作用没有显著影响,水稻对萘胁迫有一定的耐受性。④经过水稻一个生长周期,萘在种子中的残留量最多,其次是根部,且土壤中萘各浓度组的残留量与对照组均无显著差异;水稻根部和种子中萘的含量均随萘浓度的增加呈先增加后逐渐降低趋势,但各浓度组均高于对照组,20mg·kg-1时均达到最大值,分别为对照组的0.37倍、4.27倍。

The effects of Naphthalene （Nap）, one of Polycyclic Aromatic Hydrocarbons （PAHs）, on the growth and physiological characteris- tics of rice（ Oryza sativa cv. Matsumae） as well as the residue of Nap in the soil at maturity were determined by comparing several morphological, physiological, biochemical indices of rice at three growth stages, and amounts of Nap in the soil, roots, seeds respectively among five different concentration of Nap stresses. The results showed that, （1） when the concentration of Nap was lower than 20 mg· kg^-1, the growth of stem diameter, stem height and plant height were promoted, but these growth were significantly inhibited under higher concentrations of Nap. （2） Nap stress seriously impacted on the proline content and protein metabolism at seedling stage, followed by tillering stage and jointing stage. Malondialdehyde（MDA） content of plants growing under Nap stresses were significantly higher than those of plants growing without Nap at seedling stage, indicating the occurrence of lipid eroxidation at this stage. At jointiug stage, rice growed new organs, with weak resistance, peroxidation resulting from Nap stress was more than the tolerance range of rice,and make a significant reduction in superoxide dismutase（SOD） activity. （3）Within the range of the conducted concentration of Nap, there were different trends of the changes of chlorophyll content and the photosynthesis rate of leaf at seedling stage and tillering stage, with less than ＋5% variation compared to the control, This insignificant effect of the Nap on the photosynthesis of Oryza sativa cv. Matsumae showed that a certain mechanism might exist to help rice to resist the Nap stress. （4）a growth period, maximum residue of Nap was found in seeds, then in the roots. The residues of the Nap in the polluted soil were similar to that of the control soil. However, increased Nap residues of the seeds and roots were found in stressed rice plants, which increased gradually at first, then decreased,with maximal 0.37 and 4.27 times（at 20 mg· kg^-1 treatment） than the control, respectively.