兰州市不同空气环境下9种园林植物叶片解剖结构特征

The Leaf Anatomical Structure of 9 Garden Plants in Different Air Environments in Lanzhou City

为探讨园林植物对大气污染环境的适应性,以兰州市安宁区银滩路的商贸居住混合区(清洁区)和深安大桥北岸的交通枢纽区(污染区)常见的9种园林植物为研究对象,包括旱柳(Salix matsudana)、紫丁香(Syringa oblata)、紫叶李(Prunus cerasifera cv.pissardii)、木槿(Hibiscus syriacus)、金叶女贞(Ligustrum×vicaryi)、红瑞木(Swida alba)、月季(Rosa chinensis)、白车轴草(Trifolium repens)和早熟禾(Poa annua),使用石蜡切片法对不同大气环境下不同生活型的9种园林植物叶片进行解剖观察和比较分析,研究不同大气环境对9种园林植物叶片结构的影响。结果表明,(1)叶解剖结构指标在各采样点间表现出不同程度的差异性,旱柳栅栏组织发达,表现出等面叶特征,其他8种植物表现出异面叶特征;除紫叶李外,其他8种植物的下角质层厚度(CTLE)均是清洁区厚于污染区,且9种植物栅栏组织厚度(TPT)污染区均比清洁区大;海绵组织厚度(TST)除金叶女贞外,其他植物均污染区小于清洁区。(2)叶厚度(TL)与TPT、TST呈极显著正相关,上角质层厚度(CTUE)与CTLE的负相关性极显著,且CTUE对TPT和TST也有一定的影响;TPT与TST呈极显著正相关关系。(3)9种园林植物解剖结构指标的变异系数和可塑性指数的均值排序一致,都为紫丁香>月季>白车轴草>早熟禾>金叶女贞>旱柳>木槿>紫叶李>红瑞木,表明9种植物的生态适应性强弱也是如此;各解剖结构中TPT、TST和栅栏组织厚度与海绵组织厚度之比(P/S)具有较大的可塑性,说明在应对不同环境时栅栏组织与海绵组织起主导作用。(4)主成分分析结果表明,抵抗和适应环境胁迫最主要的场所是叶肉组织,且叶肉组织的分化程度也可用P/S来评估。研究结果可为城市园林植物的选择与配置提供科学的依据。

In order to explore the adaptability of garden plants to the air polluted environment,9 common garden plants in the commercial and residential mixed area(clean area)on Yintan Road,Anning District,Lanzhou City and in the transportation hub area(polluted area)on the north bank of Shen'an Bridge are the research materials,including Salix matsudana,Syringa oblata,Prunus cerasifera cv.pissardii,Hibiscus syriacus,Ligustrum×vicaryi,Swida alba,Rosa chinensis,Trifolium repens and Poa annua.Paraffin section was used to observe and compare the leaves of 9 garden plants with different life forms in different air environments,and different effects of atmospheric condition on the leaf structure of 9 garden plants.The results showed that:(1)Leaf anatomical structure indexes showed various degrees of difference among the sampling sites.Palisade tissue of Salix matsudana was developed,showed isofacial leaf characteristics.The other eight plants showed heterofacial leaf characteristics.Except Prunus cerasifera cv.pissardii,the lower cuticle thickness(CTLE)of the other 8 plants was thicker in clean area than that in polluted area.Fence tissue thickness(TPT)of the plants in polluted area was thicker than that in clean area.Thickness of spongy tissue(TST)was thinner of plants in polluted area than in clean area except Ligustrum×vicaryi.(2)Leaf thickness(TL)has a very significant positive correlation with TPT and TST.Superior stratum corneum thickness(CTUE)has a very significant negative correlation with CTLE,and CTUE also has a certain effect on TPT and TST.TPT and TST have a very significant positive correlation.(3)Order of variation coefficient and plasticity index of nine garden plants was Syringa oblata>Rosa chinensis>Trifolium repens>Poa annua>Ligustrum×vicaryi>Salix matsudana>Hibiscus syriacus>Prunus cerasifera cv.pissardii>Swida alba,which indicated that the ecological adaptability of the nine plants was the same.The ratio of TPT,TST and palisade tissue thickness to sponge tissue thickness(P/S)in each anatomical structure has great plasticity.It shows that palisade tissue and spongy tissue play a leading role in different environments.And(4)the results of principal component analysis showed that mesophyll tissue was the most important site to resist and adapt to environmental stress,and the differentiation degree of mesophyll tissue could also be evaluated by P/S.The results can provide scientific basis for the selection and configuration of urban landscape plants.