融雪剂对大叶黄杨生长和生理特性的影响

为了研究融雪剂对道路绿化植物的影响,以大叶黄杨（Euonymus japonicus Thunb）为研究材料,研究了其在3种融雪剂（JLR-01、LBR-4、芦笛一号）不同施用量影响下的生长量和生理特性。结果表明：随着融雪剂LBR-4和芦笛一号的施用量的增大,大叶黄杨叶片的相对生长量和株高相对生长量、光合速率（Pn）、水分利用效率（WUE）、蒸腾速率（Tr）和气孔导度（Gs）随之减小,而低施用量的融雪剂JLR-01对大叶黄杨生长量、Pn、WUE和Tr有促进作用。随着融雪剂作用时间的延长,3种融雪剂的Pn和WUE也随之减小,Tr则是先减小后有所增大。当融雪剂施用量较小和胁迫时间较短时,Pn下降是因为气孔关闭;而当施用量较大和胁迫时间较长时,Pn下降是因为叶肉同化能力下降;3种融雪剂对大叶黄杨的胁迫程度由大到小的次序为：芦笛一号〉LBR-4〉JLR-01;大叶黄杨对3种融雪剂施用量的忍耐阈值在80 g.m-2左右,大叶黄杨对施用LBR-4和芦笛一号的耐受时间阈值大约为3周,对施用JLR-01的耐受时间阈值为3周以上。

Effects of snow melting agent on growth and physiological characteristics of Euonymus japonzcus Thunb

To explore the influence of snow melting agent on road-side greening vegetation,Euonymus japonzcus Thunb was adopted as the research material in this study.The growth and physiological features of Euonymus japonzcus Thunb with the applica-tions of three snow melting agents（JLR-01,LBR-4 and Reed No.1） at different application amounts were studied.The results showed that,as the application amount of LBR-4 and Reed No.1 increased,the relative growth of the leaves of Euonymus japonzcus Thunb,the relative growth of the stem,photosynthetic rate（Pn）,water utilization rate（WUE）,transpiration rate（Tr） and the stomatic conductance（Gs） declined.On the contrary,JLR-01 at small application amount promoted the growth of Euonymus japonzcus Thunb,Pn,WUE and Tr.As the action of snow melting agent continued,Pn and WUE for all of the three snow melting agents declined corre-spondingly,while Tr at first decreased and then increased to a certain extent.At small application amount of snow melting agents and with shorter stress time,the reduction of Pn could be attributed to stomatic closure;at large application amount and with longer stress time,Pn declined because the assimilative capacity of the mesophyll dropped.The decreasing order of the three snow melting agents in terms of the degree of stress exerted on Euonymus japonzcus Thunb was as follows： Reed No.1 LBR-4JLR-01.The tolerance threshold of Euonymus japonzcus Thunb with respect to the application amount averaged about 80 g.m-2;the tolerance time threshold of Euonymus japonzcus Thunb was 3 weeks for both LBR-4 and Reed No.1 and above 3 weeks for JLR-01.