地面臭氧污染对树木叶片组织结构的影响

发布时间：2018-07-09 22:54

本文选题：O_3 + 木本植物　；参考：《北京林业大学》2016年硕士论文

【摘要】：近年来由于人为活动的影响,地面臭氧(O_3)污染越来越严重,已经对植物生长造成了影响,同时对植物叶片的组织结构产生了损害,本文通过对开顶式O_3熏气室处理18种亚热带常见树种叶片进行组织结构观测,利用莱卡DM2500观察受害叶片的组织结构,LAS V4.5 (Leica Application)软件照相并测量栅栏组织厚度、海绵组织厚度、上表皮厚度、下表皮厚度、叶片总厚度5个指标,计算出栅栏组织与海绵组织的比值,SPSS19.0处理数据。分析了有O_3伤害症状叶片和无O_3伤害症状叶片的组织结构之间的差异以及树木叶片抗地面O_3污染的能力,进一步探索了地面O_3污染对植物生长的影响。结果显示：(1)植物受到O_3伤害后其叶片表现出如下的可见症状及症状变化趋势：大部分植物叶片均有褪绿的现象,并且是由叶缘叶尖逐渐向内扩散,在细叶脉间偶尔会有斑点或斑块,均匀或不均匀的分布,褐色、黄色、黑色斑点斑块,叶背面偶有轻微褪绿现象,在叶脉上没有表现出伤害症状；(2)在O_3污染的环境条件下,叶片上虽没有表现出O_3伤害症状,但是试验证明叶片的组织结构已经发生了显著变化,18种植物受O_3伤害后有症状与无症状叶片的栅栏组织厚度、海绵组织厚度均发生显著变化,并且两者的厚度变化情况一致,其中厚度显著增加的约为39%,叶片厚度变化情况与栅栏组织厚度、海绵组织厚度的变化情况保持一致,O_3对同一叶片内各组织的伤害程度有的对栅栏组织伤害程度大于海绵组织(如海州常山、柔毛泡花树等),有的海绵组织的伤害程度大于栅栏组织(如七叶树、粉团等)；(3)利用生物显微镜观察叶片的显微结构发现,有O_3伤害症状与无O_3伤害症状叶片的维管束组织均没有被破坏,无O_3伤害症状叶片内的全部叶绿体、细胞核仍然保持完整,但是有O_3伤害症状叶片内部分叶绿体、细胞核出现解体现象;(4)具有抗O_3能力的有5种,即栅栏组织与海绵组织的比值升高有5种树木；栅栏组织与海绵组织的比值降低和不变的有13种。(5)在O_3熏蒸室内熏蒸宜昌楠叶片结果显示：标准空气与当地空气处理过的无症状的叶片结构进行比较,栅栏组织、海绵组织、叶片、下表皮厚度均极显著增加,分别增加了37.57%、14.19%、9.44%、22.42%,上表皮厚度极显著降低了58.23%；当地空气处理过的有症状与无症状叶片进行比较栅栏组织、海绵组织、叶片厚度均极显著增加,分别增加了7.97%、25.02%,上、下表皮变化不显著。45nmol·mol-1的O_3浓度与当地空气有、无症状叶片的栅栏组织/海绵组织比较,比值均增加,但是在当地空气处理的情况下叶片有无症状的栅栏组织/海绵组织比值下降。
[Abstract]:In recent years, as a result of human activities, surface ozone (O _ 3) pollution has become more and more serious, which has had an impact on plant growth and on the tissue structure of plant leaves. In this paper, the tissue structure of leaves of 18 common subtropical tree species treated with open top O3 fumigation chamber was observed. The tissue structure of injured leaves was observed by Laika DM2500. The thickness of palisade tissue and sponge tissue were measured by the software of Las V4.5 (Leica Application). The ratio of palisade tissue to spongy tissue was calculated by SPSS 19.0 processing data, including the thickness of upper epidermis, the thickness of lower epidermis and the total thickness of leaves. The difference of tissue structure between the leaves with and without O _ 3 injury symptom and the ability of tree leaves to resist surface O _ 3 pollution were analyzed, and the effects of surface O _ 3 pollution on plant growth were further explored. The results showed that: (1) the plant leaves showed the following visible symptoms and the tendency of symptom change after being injured by O _ S3: most of the plant leaves showed the phenomenon of chlorosis and gradually spread from the tip of the leaf edge to the inner part of the leaf. Occasionally there are spots or plaques among fine veins, evenly or unevenly distributed, brown, yellow, and black spots, with occasional slight chlorosis on the back of the leaves, showing no signs of injury on the veins; (2) under the environment polluted by Oste3, Although there were no symptoms of O _ 3 injury in leaves, the results showed that the tissue structure of leaves had changed significantly. The palisade tissue thickness and spongy tissue thickness of symptomatic and asymptomatic leaves of 18 species of plants had changed significantly after O _ 3 injury. And the thickness changes of the two groups are consistent, and the thickness of the palisade tissue are significantly increased by about 39% of the thickness of the leaf. The change of sponge tissue thickness is consistent. Some of the damage degree to palisade tissue is greater than that of sponge tissue (E. g., Changshan, Haizhou). In some cases, the damage degree of sponge tissue was greater than that of palisade tissue (such as); (_ 3), and the microscopic structure of leaves was observed by biomicroscopy. The vascular bundle tissues with and without O _ 3 injury symptoms were not destroyed. All chloroplasts in leaves without O _ 3 injury symptoms, the nucleus remained intact, but some chloroplasts in leaves with O _ 3 injury symptoms. (4) there were 5 species of trees with the ability to resist O _ 3, that is, the ratio of palisade tissue to spongy tissue was increased, and there were 5 species of trees with higher ratio of palisade tissue to spongy tissue. The ratio of palisade tissue to spongy tissue decreased and remained unchanged in 13 species. (5) the results of fumigation in O _ 3 fumigation room showed that standard air was compared with the asymptomatic leaf structure treated with local air, palisade tissue, spongy tissue, palisade tissue, spongy tissue, The thickness of the lower epidermis increased significantly, and the thickness of the upper epidermis increased by 37.57% 14.19% and 22.422.The thickness of the upper epidermis decreased significantly by 58.23.The palisade tissue was compared between the symptomatic and the asymptomatic leaves treated by the local air, and the thickness of the sponge tissue and the leaf was significantly increased. Compared with the palisade tissue / spongy tissue of the asymptomatic leaves, the ratio of O _ 3 in the upper and lower epidermis of 0.45 nmol / mol-1 was increased, respectively, compared with that of the local air, and the ratio of the palisade tissue to the spongy tissue of the asymptomatic leaves was increased. However, the ratio of palisade tissue to spongy tissue was decreased when the leaves were treated with local air.
【学位授予单位】：北京林业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X51;S718.45

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