The Identification Of Five Kinds Of Perennial Flowers In Drought Resistance In Northern Region

In recent years,drought has become the biggest constraint for landscaping construction in most parts of northern.The plant allocation pattern with low water consumption and aesthetics has become the main direction of greening construction in northern China.When selecting green plant materials,perennial flowers are valued by landscaping for their strong resistance to stress and the ability of growing.Firstly,we adopt five kinds of common perennial flowerswith high ornamental value and cold tolerance as test material.And we divided these flowers into two types:mesophytes and xerophytes.Secondly,we controlled the amount of water poured in pot and measuring the soil water content and recording the status of flowers growth at various time points.Meanwhile,the activity of leaf SOD,the content of Pro,soluble protein,soluble sugar and MDA were determined by Perennial flowers leaf.Thirdly,the membership function analysis method was used to compare the drought resistance of five kinds of perennial flowers.The order is as follows:Allium schoenoprasum>Allium senescens>Salvia prattii>Veronica xilinensis>Lythrumsalicaria.At the same time,we use the principal component analysis method to know the physiological and biochemical indexes that can reflect the drought resistance of five kinds of Perennial flowers were as follows:The content of MDA;The relative saturated loss of leaves;The content of soluble sugar;The SOD activity;The content of Pro and soluble protein..Finally,we sum up such conclusions and finding the most suitable environment of each perennial flowers.The results showed that the five perennial flowers has different degrees of wilting and shrinking under drought stress.Lythrumsalicaria was the most affected by drought stress.But Allium schoenoprasum was less affected by drought than other perennial flowers.At the same time,the volumetric water content of the five kinds of perennial flowers showed a trendency that decreasing fastly and then slowly.Allium schoenoprasum and Allium senescens the lowest soil water content In this fives kinds of perennial flowers.Meanwhile their the soil water content are 4.37%and 3.7%respectively.The results of measuring the physiological indexes of the five kinds of perennial flowers at each time point are as follows:(1)The relative saturated loss of leavesUnder drought stress,the five species of Perennial flowers showed an upward trend in relative water saturated loss of leavesand the increase of mesophytes was greater than xerophytes.The water saturation loss of Veronica xilinensisare 61.48%which is the high level in the five kinds of perennial flowers When the soil water status was similar.(2)The SOD activityDuring the experiment,the activity of SOD in the five kinds of perennial flowers increased first and then decreased.At the same time,the the activity of SOD of xerophytes are high and more complicated than mesophytes.When the soil moisture conditions are similar,the activity of SOD of Allium schoenoprasum and Allium senescens are the highest among the five perennial flowers,which are 37.75%and 28.74%.(3)The content of ProThe content of Pro of five kinds of perennial flowers leaves are increased during drought stress.The content of Pro of Veronica xilinensis and Lythrumsalicariare the highest,which were 352.63?g/g and 344.38?g/g,When the soil moisture conditions were similar.(4)The content of soluble proteinThe content of soluble protein in the mesophytes decreased firstly and then decreased during drought stress,while the two types of xerophytes showed a trend of increasing first,then decreasing and then rising.At the same time,when the water conditions were similar,the soluble protein content of the leaves of Salvia prattii is the highest,reaching 1.71 mg/g;the soluble protein content of the leaves of Allium senescens is 0.53,which is the lowest soluble protein content of the five kinds of perennial flowers.(5)The content of soluble sugarThe soluble sugar content of the five kinds of perennial flowers increased under drought stress.The rising trend of Salvia prattii is stronger than other mesophytes and reaching the highest value of 1.43%.The changes of the two xerophytes are relatively flat.(6)The content of MDAUnder the drought stress,the content of MDA of the five species of perennial flowers are increased.The change trend Lythrumsalicaria is the most severe.The content of MDA of the two xerophytes is slightly more complex than other mesophytes,which alternated with rising and falling.