干旱胁迫对2种地被植物生理指标的影响

Effects of Drought Stress on Physiological Indexes of Two Ground Cover Plants

为丰富太原市园林地被植物种类,在园林绿化中合理选择和应用地被植物,以太原市新引种栽培并经过评价筛选的八宝景天和金娃娃鸢尾为试材,采用自然干燥控水法,在持续干旱胁迫下,观察植株形态变化,并测定离体叶片失水速率、相对含水量、细胞质膜透性、叶绿素含量、可溶性蛋白含量、丙二醛含量、SOD活性、POD活性等生理指标,通过生理指标的变化,探究2种地被植物对干旱胁迫的生理响应,分析二者的抗旱能力。结果表明,从形态变化来看,金娃娃鸢尾较好;从水分生理指标来看,金娃娃鸢尾具有较好的保水和抗脱水能力;叶绿素含量变化总体下降,其中,八宝景天下降幅度较小,表现为先下降后升高,而金娃娃鸢尾表现为先上升后下降;从细胞质膜透性看,八宝景天和金娃娃鸢尾的电导率均上升,上升幅度分别为66.8%和64.9%;八宝景天和金娃娃鸢尾可溶性蛋白含量均呈上升趋势,上升幅度分别为44.9%和56.1%;八宝景天和金娃娃鸢尾的丙二醛含量都呈上升趋势,分别增加了1.49倍和1.33倍;2种地被植物的SOD和POD活性均呈现先升高后下降的趋势,但八宝景天的SOD和POD活性峰值均出现在干旱胁迫14 d时,金娃娃鸢尾的SOD和POD活性峰值分别出现在干旱胁迫21、14 d时。综合各生理指标认为,八宝景天和金娃娃鸢尾均有较强的耐旱能力,其中,金娃娃鸢尾的耐旱能力更强。

To enrich garden ground cover plant species in Taiyuan,and select and apply the ground cover plants reasonably in landscaping,taking the cultivated and evaluated plants,Sedum spectabile and Iris germanica as the testing material,the experiment observed morphological changes and measured the physiological indexes,including water loss rate,relative water content,plasma membrane permeability,chlorophyll content,soluble protein content,malondialdehyde content,SOD activity and POD activity of detached leaves under drought stress.Through the changes of physiological indexes,the experiment explored two garden cover plants physiological response to drought stress,and analysed the drought-resistant ability.The results showed that from the morphological changes,Iris germanica was more drought resisting.From water loss rate and relative water content,Iris germanica had good water retention and dehydration resistance.From the chlorophyll content,they both showed a downward trend,Sedum spectabile showed less of a drop,which first decreased and then increased,but the performance of Iris germanica first increased and then decreased.In terms of the cell cytoplasmic membrane permeability,the EC of Sedum spectabile and Iris germanica both increased,with 66.8%and 64.9%,respectively.In terms of soluble protein content,Sedum spectabile and Iris germanica both increased,with 44.9%and 56.1%,respectively.In terms of MDA content,Sedum spectabile and Iris germanica both showed an increasing trend,with 1.49 times and 1.33 times.The SOD and POD activities of both ground cover plants first increased and then decreased.However,the peak values of SOD and POD activities of Sedum spectabile both appeared at the drought stress of 14 d,while the peak values of SOD and POD activities of Iris germanica appeared at the drought stress of 21 d and 14 d,respectively.On the basis of the physiological indexes,it can be concluded that Iris germanica has stronger drought resistance than Sedum spectabile.