中国北方6种常见蕨类植物耐热性研究

A Study on Heat Tolerance of Six Fern Species from Northern China

利用电导率、半致死温度、细胞伤害率等参数,比较北方6种蕨类植物的耐热性,以期为蕨类植物在北方夏季高温环境园林景观布置中的材料选择提供依据。选择蕨、球子蕨、荚果蕨、粗茎鳞毛蕨、广布鳞毛蕨和中华蹄盖蕨进行耐热胁迫处理,测定叶片相对电导率,使用Logistic方程确定LT50,同时测定蕨类植物的叶表皮结构(叶面积、叶比重、气孔密度)、叶绿素含量、光合特性参数等,分析蕨类植物耐热性与各测定指标之间的相关性,再利用夏季的田间观察数据检验,并结合蕨类植物的地理分布特征,综合评估各试验材料的耐热性。结果表明,温度升高后,测试材料的细胞伤害率呈慢、快、慢的“S”形曲线变化。6种蕨类的高温半致死温度为粗茎鳞毛蕨(63.77℃)>中华蹄盖蕨(62.07℃)>广布鳞毛蕨(61.63℃)>荚果蕨(61.13℃)>球子蕨(58.10℃)>蕨(56.70℃)。田间观察数据与电导率法检测数据基本相符,并与蕨类地理分布特征基本保持一致,LT50可以作为蕨类耐热性的评价依据之一。蕨类叶片的表皮形态指标也可以作为其耐热性的参考。筛选结果可丰富蕨类植物在北京地区园林展示中的应用种类。

In order to guide the selection of fern materials for landscape in the summer high-temperature environment of northern China,this study compared the heat resistance of six native fern species from northern China using parameters such as electrical conductivity,half-lethal temperature,and cell damage rate.Pteridium aquilinum var.latiusculum,Onoclea sensibilis var.interrupta,Matteuccia struthiopteri,Dryopteris crassirhizoma,D.expansa,and Athyrium sinense were selected for heat stress treatment.The relative conductivity of them was determined under gradient temperature treatment conditions,and the half-lethal temperature(LT50)was calculated by a Logistic equation.Simultaneously,measurements of fern leaf epidermis structure(leaf area,leaf weight,stomata density),chlorophyll content,and photosynthetic data were also conducted.On such a basis,the correlation between the heat resistance of ferns and each measurement indicator was analyzed and then tested using field observation data.Combining with geographical distribution characteristics of ferns,the thermal resistance of each experimental material was comprehensively evaluated.The results showed that with the increase of temperature,the cell damage rate showed an‘S’curve(slow-fastslow).The ranking of six fern species based on half-lethal temperature ranges from highest to lowest was as follows:D.crassirhizoma(63.77℃)>A.sinense(62.07℃)>D.expansa(61.63℃)>M.struthiopteris(61.13℃)>O.sensibilis var.interrupta(58.10℃)>P.aquilinum var.latiusculum(56.70℃).The field observation data were generally consistent with the conductivity data and the geographical distribution characteristics of ferns.LT50 could be used as one of the evaluating factors for the heat tolerance of ferns.The epidermal morphology of leaves can also be used as a reference for heat tolerance.The selection results can enrich the types of ferns used in garden display in Beijing.