干旱胁迫对6种灌木生理特征的影响

Effects of drought stress on physiological characteristics of six shrubs

以天目琼花、麻叶绣线菊、小紫珠、京山梅花、胡枝子和金银忍冬为试验材料,研究干旱条件下6种灌木的生理特征。结果表明:6种灌木叶水势与土壤含水量具有极显著相关性,随着土壤含水量的下降6种灌木叶水势随之下降,说明土壤含水量是决定植物叶水势的关键性因素。随着土壤含水量的下降,6种灌木叶相对含水量逐渐下降,下降幅度由小到大依次为:天目琼花<金银忍冬<京山梅花<麻叶绣线菊<小紫珠<胡枝子;6种灌木叶水分饱和亏、叶肉质化程度和比叶面积逐渐增大,增加幅度由小到大依次为:天目琼花<金银忍冬<京山梅花<麻叶绣线菊<小紫珠<胡枝子。基于土壤水分判别模型可知,天目琼花为亚高水势延迟脱水耐旱树种;麻叶绣线菊、小紫珠和胡枝子为低水势忍耐脱水耐旱树种;京山梅花为高水势延迟脱水耐旱树种;金银忍冬为亚低水势忍耐脱水耐旱树种。应用主成分分析法对6种灌木抗旱能力进行综合评价,得出6种灌木抗旱能力大小为:天目琼花>金银忍冬>麻叶绣线菊>京山梅花>小紫珠>胡枝子。

The physiological characteristics of six shrubs under drought conditions were studied with the experimental materials of Viburnum opulus subsp.calvescens,Spiraea cantoniensis,Callicarpa dichotoma,Philadelphus pekinensis,Lespedeza bicolor and Lonicera maacki.The results showed that leaf water potential of six shrub species was significantly correlated with soil water content,and the leaf water potential of six shrub species decreased with the decreased of soil water content,indicated that soil water content was the key factor determined the leaf water potential of plants.With the decreased of soil water content,the relative water content of six shrub leaves decreased gradually,and the decreasing range was as follows:Viburnum opulus subsp.calvescensLonicera maackiiPhiladelphus pekinensisSpiraea cantoniensisCallicarpa dichotomaLespedeza bicolor.With the decreased of soil water content,the leaf water saturation deficit,degree of leaf succulence and specific leaf area of the six shrubs increased gradually and the increasing range was as follows:Viburnum opulus subsp.calvescens Lonicera maackiiPhiladelphus pekinensis Spiraea cantoniensisCallicarpa dichotomaLespedeza bicolor.Based on soil moisture discrimination model:Viburnum opulus subsp.calvescens was a drought tolerant species with subhigh water potential and delayed dehydration;Spiraea cantoniensis,Callicarpa dichotoma,Lespedeza bicolor were species with low water potential and tolerance to dehydration and drought;Philadelphus pekinensis was a drought tolerant tree with high water potential and delayed dehydration;Lonicera maackii was a tree with low water potential and tolerance to dehydration and drought.The drought-resistant capacity of six shrubs was comprehensively evaluated by principal component analysis,and the drought-resistant capacity of the six shrubs was as follows:Viburnum opulus subsp.calvescensLonicera maackiiSpiraea cantoniensisPhiladelphus pekinensisCallicarpa dichotomaLespedeza bicolor.