干旱胁迫下保水剂对3种扶芳藤生长和生理特性的影响

Effects of water retaining agent on physiological characteristics of three Euonymus plants under drought stress

【目的】探究干旱胁迫下保水剂对3种扶芳藤植物生长和生理的影响,为园林植物的抗旱途径提供理论依据。【方法】以扶芳藤Euonymus fortunei(Turcz.)Hand.-Mazz.、爬行卫矛Euonymus fortunei var.radicans、金边扶芳藤Euonymus fortunei‘Emerald Gold’为材料,设置4种保水剂梯度(保水剂与基质的质量比分别为0.3%、0.6%、0.9%、1.2%)和不施用保水剂为对照(CK),研究了不同保水剂量下3种植物的生长形态指标(株高和新芽数量)、光合生理(总叶绿素、叶绿素a、叶绿素b)、水分生理(相对含水量RWC、相对电导率)、逆境生理(丙二醛MDA、脯氨酸Pro、可溶性蛋白SP、超氧化物歧化酶SOD)的响应特性。【结果】1)在干旱胁迫下,保水剂能显著提高扶芳藤、爬行卫矛、金边扶芳藤3种扶芳藤植物的株高,其株高增加了3.6~6.0 cm,其新芽数量增加了4~7根,延长其存活时间10~20 d。2)与CK相比,保水剂能显著提高总叶绿素含量和叶绿素a/b值,不同保水剂含量对总叶绿素含量和叶绿素a/b值有显著性差异,高保水剂量比低保水剂量对叶片总叶绿素含量和叶绿素a/b值提高更有效。3)保水剂能显著提高相对电导率和相对含水量,低保水剂量植物对干旱胁迫最先响应,受害程度相对严重,而高保水剂量植物响应较晚,且受害程度较轻。4)保水剂能显著降低丙二醛的含量,能显著提高植物的可溶性蛋白、可溶性糖、游离脯氨酸等渗透物质的含量,能显著提高植物SOD酶活性。5)扶芳藤在0.6%保水剂量时的保水效果最好,爬行卫矛和金边扶芳藤在0.9%的保水剂量时的保水效果最好。【结论】在干旱胁迫下,一定质量比的保水剂能增加3种扶芳藤的株高生长和新芽数量,有效提高3种植物的抗旱性,延长其存活时间。

【Objective】To explore the effects of HRD water-retaining agent on the growth and physiology of three species of Euonymus fortunei under drought stress,and to provide theoretical basis for drought resistance of garden plants.【Method】E.fortunei(Turcz.)Hand.-Mazz,E.fortunei var.radicans,E.fortunei‘Emerald Gold’were used as materials with four water-retaining agent gradients(the mass ratio of water-retaining agent and base material was 0.3%,0.6%,0.9% and 1.2%,respectively)and no water-retaining agent was used as control(CK).The response characteristics of growth morphological indexes(plant height and number of new shoots),photosynthetic physiology(total chlorophyll,chlorophyll a,chlorophyll b),water physiology(RWC,relative conductivity)and stress physiology(MDA,PRO,SP,SOD)of three plants under different water retention doses were studied.【Result】1)Under drought stress,the water-retaining agent significantly increased the plant height of three species of Euonymus by 6 cm,3.6 cm,3.6 cm,respectively,and the number of new buds was 5,7,4,and the survival time was prolonged for 10-20 days;2)Compared with CK,water-retaining agent significantly increased total chlorophyll content and chlorophyll a/b value.Different water-retaining agent contents had significant differences in total chlorophyll content and chlorophyll a/b value.High water-retaining dose was more effective than low water-retaining dose in improving total chlorophyll content and chlorophyll a/b value;3)Water-retaining agent significantly improved the relative conductivity and relative water content.Low water-retaining dose plants responded to drought stress first and the damage degree was relatively serious,while high water-retaining dose plants responded later and the degree was relatively light;4)Water-retaining agent significantly increased the content of MDA,soluble protein,soluble sugar,free proline and other osmotic substances,and significantly increased the activity of SOD;5)The principal components of different water-retaining doses showed that the water-retaining effect of Euonymus crawling and Euonymus Phnom Penh was the best when the water-retaining dosage was 0.6%,and the water-retaining effect of Euonymus crawling and Euonymus Phnom Penh were 0.9%.【Conclusion】Under drought stress,a certain concentration of waterretaining agent can promote the morphological growth of Euonymus,effectively improve the drought resistance of the three plants and prolong their survival time.