5种观花园林树木对NO_(2)的抗性评价

Assessment of NO_(2) Resistance of Five Ornamental Garden Trees

为阐明5种观花园林树木耐NO_(2)污染机制,科学评价植物抗NO_(2)污染能力以及指导园林绿化科学选择植物,采用开顶式熏气的方法对日本晚樱(Cerasus serrulata var.lannesiana(Carr.)Makino)、紫荆(Cercis chinensis Bunge)、紫叶桃(Amygdalus persica L.‘Atropurpurea’)、春鹃(Rhododendron mucronatum(Bl.)G.Don)和紫薇(Lagerstroemia indica L.)5种观花园林树木的3年生苗木进行不同浓度的NO_(2)胁迫,研究了被试植物在不同质量浓度的NO_(2)胁迫条件下叶片净光合速率、气孔导度、蒸腾速率、相对叶绿素含量、细胞膜透性、MDA含量、SOD和POD酶活性等生理指标的变化,并采用模糊数学隶属函数法和灰色关联度法对其抗NO_(2)能力进行了综合评价.结果表明,随着处理质量浓度的增加,5种观花园林树木的各项指标变化模式不同.植物叶片净光合速率、气孔导度、蒸腾速率、相对叶绿素含量、SOD和POD酶活性随着NO_(2)胁迫加剧,其变化趋势基本相似,均是先上升后下降;细胞膜透性和MDA含量的变化趋势均总体上升.隶属函数值从大到小依次为:紫叶桃、春鹃、紫薇、日本晚樱、紫荆.在所选的8个指标中,MDA含量、细胞膜透性、SOD酶活性、POD酶活性等指标均可作为观花园林植物对NO_(2)抗性的重要鉴定指标.

In order to elucidate the mechanism of NO_(2) tolerance of five kinds of ornamental trees,scientifically evaluate the ability of the plants to resist to NO_(2) pollution,and guide the scientific selection of plants for landscaping,an artificial simulation method was employed to treat three-year-old saplings of five ornamental garden plants species,Cerasus serrulata var.lannesiana(Carr.)Makino,Cercis chinensis Bunge,Amygdalus persica L.‘Atropurpurea’,Rhododendron mucronatum(Bl.)G.Don and Lagerstroemia indica L.with different concentrations of NO_(2).The symptoms of acute injury were observed.The net photosynthetic rate,stomatal conductance,transpiration rate,relative chlorophyll content,cell membrane permeability,MDA content,SOD and POD activity were measured.The methods of subordination function and grey correlation analysis were used to comprehensively evaluate the resistance to NO_(2).The results showed that with the increase of NO_(2) concentration,the change patterns of each index of five garden trees were different.The change of the trends of net photosynthetic rate,stomatal conductance,transpiration rate,relative chlorophyll content,SOD and POD enzyme activities of leaves were basically similar with the increasing of NO_(2) stress,which increased first and then decreased.The trends of cell membrane permeability and MDA content were generally increasing.The tolerance of tested tree species to NO_(2) was in an order of Amygdalus persica L.‘Atropurpurea’,Rhododendron mucronatum(Bl.)G.Don,Lagerstroemia indica L.,Cerasus serrulata var.lannesiana(Carr.)Makino,Cercis chinensis Bunge.Among the eight selected indexes,MDA content,cell membrane permeability,SOD enzyme activity,and POD enzyme activity can be used as important indicators to identify the NO_(2) resistance of ornamental forest plants.