Study On Drought Resistance Of 16 Species Of Landscape Plants By PV Technique

At present, as the global water conservation advocate with call and in the lack of water resources, plant drought tolerance of supply and demand is becoming more and more vigorous, selection of drought resistant plants in garden greening has attracted more and more people’s attention. So on plant were study on drought resistance, and to explore the plant is how the external morphology and internal physiological and biochemical responses to resist drought stress is modern water-saving irrigation in urban green space landscape construction urgent need to solve the problem, and to provide a theoretical basis for the construction of urban green space landscape plant material.In this paper, Using Zygophyllum xanthonylon、Artemisia sphaerocephala Periploca sepium、Tamarix ramosissima、Platycladus orientalis、Salix gordejevii、 Salix cheilophila、Caryopteris mongholica、Caragana korshinskii、Elaeagnus angustifolia、Ampelopsis brevipedunculata、Salix cheilophila、Hedysarum mongolicum、Artemisia ordosica、Caragana microphylla、Atraphaxis frutescens And so on 16 kinds of garden plants as the experimental materials, the use of P-V technology to determine the water physiological parameters, The saturated water content when the maximum osmotic potential (Ψssat), incipient plasmolysis point osmotic potential (Ψstlp), incipient plasmolysis point relative containing water (RWCtlp), relative permeability and water content (ROWCtlp) and elastic modulus (εmax) of incipient plasmolysis point and analysis of 16 kinds of experimental materials of water physiological parameter difference. Because of the different results of the drought tolerance of different water physiological parameters derived from plants, so finally, we use the principal component analysis of membership function and the method of experimental species in different physiological water parameters of integration, replacing other place and got the comprehensive evaluation on the drought resistance of plants In order to provide a theoretical basis for the selection and cultivation of plants in the urban green space construction, the main results are as follows:1. The five kinds of water physiological parameters respectively for 16 kinds of plant drought resistance was evaluated and that different parameters of the water in the drought resistance of the plant arrangement exists significant differences. For example, in the saturated state of the overall osmotic potential, the drought resistance of Cortex Phellodendri was the strongest, and in the elastic modulus of the water physiological indexes that greatly reduced the drought resistance of Cortex Phellodendri. Single physiological and biochemical factors difficult to plant to drought tolerance evaluation.2. On 16 species of garden plants of 5 kinds of drought resistance index of principal component analysis, further drought resistant physiological indexes of comprehensive evaluation, according to the characteristic value is greater than or equal to 1 from two principal components, with two new variables instead of the original five variables, calculations for the winner of the component model, and using the model obtained five indexes of drought resistance of ranking from high to low in order to εmax、ROWCtlp、ΨSsat、ΨStlp、RWCtlp, shows in five kinds of water physiological parameters in plants of the maximum modulus of elasticity in the study on drought resistance is important. In plant water physiology of the elastic modulus of the High value to reflect the characteristics of cell wall tissue. The experimental results can be seen Artemisia ordosica, Caragana, Caryopteris mongolica and Overlord cell wall soft, greater flexibility, under drought conditions can rapid contraction, is conducive to maintaining a higher turgor, maintain the normal life activities, which is the passive tolerance to drought; and Artemisia sphaerocephala, Cortex Phellodendri, snake grapes and Periploca εmax value although greater flexibility in a small cell wall hard, but to maintain cell moisture, avoid drought conditions in the lower part of the body of water excessive loss, the initiative to adapt to drought.3. Due to drought resistance mechanism is different among species and among the indices may exist different of correlation, which makes the evaluation results differ to varying degrees. Illustrate this, can not be used single index to evaluate the drought resistance of landscape plants, and to fully integrate all factors on plant drought tolerance evaluation, more reliable results.In the end of this paper, using the membership function method to evaluate the drought tolerance of plants, it is concluded that the drought the experimental tree species is from strong to weak: Artemisia ordosica> Atraphaxis frutescens> Hedysarum mongolicum>Zygophyllum xanthonylon>Caryopteris mongholica>Periploca sepium>Elaeagnus angustifolia> Tamarix ramosissima>Ampelopsis brevipedunculata> Caragana microphylla> Caragana korshinskii>Salix gordejevii>Salix cheilophila>Salix cheilophila>Artemisia sphaerocephala>Platycladus orientalis.