【作者】 刘清丽；

【导师】 王建明；

【作者基本信息】 山西农业大学 ， 植物病理学， 2003， 硕士

【摘要】 本实验以12种重要的粮食和蔬菜作物为研究对象，研究了主要大气污染物二氧化硫（SO₂）对不同植物的伤害症状、剂量反应、伤害阈值以及影响因素，测定了抗性和敏感植物在受到SO₂污染后植物体内过氧化物酶（POD）、过氧化氢酶（CAT）、丙二醛（MDA）、可溶性蛋白质、游离脯氨酸和叶绿素的动态变化，并分析了这些生理生化变化和植物抗性的相互关系，同时还对5种化合物溶液对植物的保护作用进行了初步研究，结果表明： 1．不同植物受到SO₂污染后其外部症状明显不同，而且受害的典型症状首先表现在叶片上。供试的12种植物叶片上出现的症状可分为即脉间扩展灰白斑型、沿脉扩展黄斑型、沿叶尖叶缘扩展卷曲型和混合型4种类型。处理剂量的高低对伤害症状类型、出现的早晚、伤害程度、伤斑分布、伤斑扩展和色泽变化等均有直接影响。 2．植物不同生育时期对SO₂的敏感性不同，植物对SO₂的抗性是子叶期＞真叶期，2片真叶期和4片真叶期对SO₂的抗性差异不显著。植物幼苗期对SO₂的敏感性可以作为其对SO₂的抗性反应的鉴别依据。 3．SO₂不同处理次数对植物的伤害程度在不同植物间或同一种植物不同处理剂量间都存在明显差异，而且随着处理次数的增加，植物受伤害的程度也会随之有一定的增加，但其增加的程度明显小于剂量增加所引起的伤害程度。 4．SO₂对植物不同叶龄叶片的伤害程度明显不同。在受害程度严重的叶片中，中龄叶所占比例最大，其次是老龄叶，刚长出尚未完全伸展的嫩叶所占比例最小，对SO₂抗性最强。 5．植物受SO₂的伤害程度是暴露时间和SO₂浓度的函数，其中伤害的临界浓度取决于暴露时间，而其时间的长短与SO₂浓度密切相关。植物的受害程度随SO₂浓度增加而增加，而且其增加程度大于暴露时间增加所引起的受害程度。SO₂浓度对植物的伤害程度起主要作用。 6.植株在2片真叶期对50:比较敏感，因此可以采用植物在2片真叶期对50:的剂量反应作为受害阂值来划分抗性类型。根据2片真叶期伤害阎值，将供试的植物抗性分为4类:l)对50:敏感的植物受害阂值（15PPm x 3h;2）较敏感的受害J司值15ppm x3卜ZOppm x 3h;3)杭性较强的受害J司值Zoppn，x 3h一25ppmX3h:4)抗性强的受害阂值>25ppmX3h。 7.植物叶片的POD酶活性在抗性和敏感植物体内动态变化明显不同。在受到50:污染后，抗性植物POD酶活性高于敏感植物，而且自我调节恢复正常状态的能力和忍受较高50:剂量的能力明显强于敏感植物。 8.不同浓度的50:熏气3h后，抗性和敏感植物体内的CAT活性均明显低于对照，而且随50:浓度的增大CAT降低的比率也随之增大，浓度越大，差别越显著，而且抗性植物体内的CAT酶活性相对高于敏感植物。 9.不同浓度的50:熏气3h后，抗性植物体内的MDA含量总体水平显著低于敏感植物，抗性植物抗膜脂过氧化的能力明显大于敏感植物。 10.在受到50:污染后，杭性和敏感植物叶片中叶绿素和蛋白质的含量均有所降低，且50:浓度越高，下降的比率越大，但敏感植物的下降比率显著大于抗性植物。 11.不同浓度的50:熏气3h后，杭性和敏感植物叶片中的游离脯氨酸含量均显著升高，并随50:浓度的增大，游离脯氨酸含量增高的比率也随之成倍增加，浓度越高，差异越明显，而且抗性植物增加比率大于敏感植物。 1 2.供试的五种化合物溶液对50:伤害都具有一定的抵御保护作用，用这些化合物溶液处理植株后，能使叶绿素含量增高，而使MDA含量下降。其中效果较显著是1 Ommol/L杭坏血酸和0.5^ol/L8一羚基啥琳。更多还原

【Abstract】 This paper Stuffed with twelve important grain and vegetable crops, studied the injury symptom, dose reaction, injury threshold value and influential factor of main pollutant SO2 on various plants, tested the dynamic transformation of POD, CAT, MDA, soluble protein, free Pro and chlorophyll of resistant plant and sensitive of these physiological biochemical transformation with plant resistant ability. Meanwhile, simply studied the protective role of the five compounds on plant. The result indicated the followings.1.The outer symptom polluted by SO2 is obviously different in various plants, and primarily appears in leaves. The symptom in the leaves of the offered twelve plants can be classified into gray spots develop between lines, yellow spots develop along line, curl along leaf tip and leaf edge and mix four types. Treat dose directly affect the injury symptom type, occurrence time, injury degree, spots distribution, spots spread and color transformation.2.The sensitivity to SO2 differs in various plant growth period. The resistant ability to SO2 in cotyledon period >real leaves period. The ability in two real leaves and four real leaves haven’t clearly difference. The sensitivity of seedlings can be identified gist3.The injury degree of diverse treat times of SO2 on plant among various plants or various doses of the same plant have obvious difference, and with the rising of treat times, the injury degree of plant increased, but the increase extent is obviously less than the injury degree result from the dose accession.4.The injury degree of SO2 on leaves in diverse mature degree differs obviously. In the heaviest injury degree leaves, mid-mature leaves are main, second are mature leaves, the fresh leaves coming out in a short while and not extending completely are the least and have strong resistant ability to SO2.5.The injury degree of SO2 on plant is a funition of the exposure time and SO2 concentration. The injury critical concentration depends on the exposure time, and the time length is closely relevant to SO2 concentration. The injury degree of plant increases with the rise of SO2 concentration, and the increase speed is higher than the injury degree result from the exposure time accession. The SO2 concentration is the first factor to the injury degree of plant.6.The plant is comparatively sensitive in two leaves period. So we can use the dose reaction to SO2 in two leaves period as the injury threshold value to classify resistant ability type. According to the injury threshold value in two real leaves period, divided the stuff plats into four types: 1) the injury threshold value of the plants sensitive to SO2≤15ppm×3h; 2) the comparatively sensitive injury threshold value 15ppm× 3h-20ppm×3h; 3)the comparatively strong resistant injury threshold value 20ppm×3h-25ppm×3h; 4)the strong resistant injury threshold value≥25ppm×3h.7.The dynamic transformation of POD activity differs obviously in resistant plant and sensitive plant. After polluted by SO2, the POD activity of resistant plant is stronger than sensitive plant’s, and the self-recover to normal condition ability and fighting comparatively high dose SO2 ability are obviously stronger than sensitive plant’s.8.After fumigation for 3h in diverse concentration SO2, the CAT activity of resistant plant and sensitive plant is obviously less than the check group, and the rate of CAT decrease rises with the rise of SO2 concentration. The CAT activity of resistant plant is comparatively stronger than sensitive plant’s.9.After fumigation for 3h in diverse concentration SO2, MDA content general level is in resistant plant is obviously lower than sensitive plant’s, and the fighting membrein grease over burn ability of resistant plant is dearly stronger than sensitive plant’s.10.After polluted by SO2, both chlorophyll and protein content in resistant plant leaves and sensitive plant leaves decrease. The higher SO2 concentration, the bigger decreased rate, and the decreased rate of sensitive plant is obviously bigger than re更多还原