淹水胁迫下6种北方花灌木光合特性及耐涝性评价

Photosynthetic characteristics and waterlogging tolerance evaluation of six northern flowering shrubs under waterlogging stress

本研究以淹水胁迫0~15 d的重瓣榆叶梅、金钟花、水栒子、小花溲疏、圆锥绣球、欧洲荚蒾6种北方花灌木为试材,测定其根系生长、植株形态、光合气体交换和叶绿素荧光参数等变化。结果显示,重瓣榆叶梅、金钟花、水栒子、小花溲疏、圆锥绣球5种花灌木根系干重、根总长、根表面积等根系指标随淹水时间的增加呈先增加后下降的趋势,欧洲荚蒾呈逐渐下降的趋势;6种花灌木的植物叶片的叶片含水率、比叶重、PSII最大光合效率(Fv/Fm)、单位反应中心吸收的光能(RC/ABS)以及潜在光合转化和利用能力(PI)等叶绿素荧光指标及净光合速率(Pn)、气孔导度(Gs)、胞间CO_(2)浓度(Ci)等光合指标较对照均减小。根据测定的指标通过主成分分析等对其耐涝性进行评价,结果表明,淹水胁迫导致植物根系发褐、腐烂;植株出现萎蔫、落叶甚至死亡;随着淹水时间的增加,6种花灌木出现不同程度的光合系统受损。主成分分析结果表明,淹水胁迫主要影响植物的根系,进一步影响植物光和系统,最终评价得出6种花灌木的耐涝性排序为欧洲荚蒾>金钟花>小花溲疏>水栒子>圆锥绣球>重瓣榆叶梅。

In this study,six northern flowering shrubs of 0-15 days of waterlogging stress,such as Prunus triloba var.plena,Forsythia viridissima,Cotoneaster multiflorus,Deutzia parviflorha,Hydrangea paniculata and Viburnum opulus were used as materials.The root growth,plant morphology,photosynthetic gas ex-change and chlorophyll fluorescence parameters were measured.The results showed that the root dry weight,root total length and root surface area of 5 flowering shrubs,such as P.triloba var.plena,F.viridissima,C.multiflorus,D.parviflorha and H.paniculata,increased firstly and then decreased with the increase of waterlogging time,while that of V.opulus showed a decreasing trend.The chlorophyll fluorescence indexes,such as leaf water content,specific leaf weight,maximum photosynthetic efficiency of Psll(Fv/Fm),light energy absorbed per unit reaction center(RC/ABS),potential photosynthetic transformation and utilization capacity(Pl),net photosynthetic rate(Pr),stomatal conductance(Gs),intercellular CO_(2) concentration(C),and other photosynthetic indexes of the six flowering shrubs leaves were decreased compared with those of controls.According to the measured indicators,the waterlogging tolerance of plants was evaluated through principal component analysis and other methods.The results showed that waterlogging stress led to browning and decay of plant roots,and plants showed wilting,falling leaves,and even death.With the increase of waterlogging time,the photosynthetic system of six flowering shrubs showed varying degrees of damage.The results of principal component analysis showed that the waterlogging stress mainly affected plant roots,and further affected plant light and system.In the final evaluation,the waterlogging tolerance of the six plants was ranked as V.opulus>F.viridissima>D.parviflorha>C.multiflorus>H.paniculata>P.trilobavar.plena.