3种园林灌木幼苗对干旱胁迫的生理响应

Physiological response of three garden plants to drought stress

针对中国北方城市干旱缺水、园林绿地植物难以保证及时灌溉的现象,选择2年生灌木金叶女贞Ligustrumvicaryi,连翘Forsythia suspensa,紫薇Lagerstroemia indica,采用盆栽方法测定了土壤自然干旱胁迫过程中影响各树种抗旱性的主要生理生化指标,利用隶属函数法对3种园林植物幼苗进行综合评定。结果表明:随土壤水分胁迫的加重,金叶女贞的叶绿素质量分数先升高后降低再升高,连翘先降低后升高,紫薇呈先升高后降低的趋势,金叶女贞和连翘在不同胁迫时期的叶绿素质量分数达到显著差异水平;金叶女贞在遭受干旱胁迫后叶肉组织相对电导率呈升高—降低—升高,连翘先降低后升高,紫薇则是逐渐升高的趋势,紫薇和连翘在不同胁迫时期,相对电导率均达显著差异水平;金叶女贞的超氧化物歧化酶活性先升高后降低,紫薇则呈先降低后升高,连翘呈升高—降低—升高趋势,3个树种均达到显著差异;可溶性蛋白质量分数均呈先下降后上升的趋势,连翘达差异显著水平;脯氨酸质量分数金叶女贞呈降低—升高—降低,连翘和紫薇则是一直升高的趋势,紫薇在不同时期达到显著差异水平。综合评价结果表明,3种灌木的抗旱性强弱为:金叶女贞>连翘>紫薇。

Because of difficulty with timely irrigation of garden plants, this research was conducted to de termine the best water-stress tolerant shrub of three types to plant in the drought prone north of China. Two-year-old potted shrubs of Ligustrum vicaryi, Forsythia suspense, and Lagerstroemia indica were chosen and treated with natural drought stress with three replications in a 3 × 3 randomized block design. Physiological characteristics were measured during the course of drought stress, and the membership function was used to assess the plants＇ complex anti-drought stress capability. Results showed that as drought stress increased, the leaf chlorophyll curve for Li. vicaryi was increase-decrease-increase （P〈0.05）, for F. suspensa was de- crease-increase （P〈0.05）, and for La. indica was increase-decrease. The curve of the relative electrolyte conductivity of the leaf tissue solution for Li. vicaryi was increase-decrease-increase, for F. suspensa was decrease-increase（P〈0.05）, and for La. indica was a constant increase（P〈0.05）. The curve of superoxide dismutase （SOD） activity for Li. vicaryi was increase-decrease, for La. indica was decrease-increase, and for F. suspensa was increase-decrease-increase, and SOD activity of different periods of the three species respectively had significant difference （P〈0.05）. Soluble protein contents of the three shrubs decreased at first and then increased, and soluble protein contents of different periods for F. suspense respectively had significant difference （P〈0.05）. The proline content of Li. vicaryi was decrease-increase-decrease （P〈0.05）while F. suspeusa and Lea indica constantly in creased. Complex appraisal of drought resistance by using membership functions for the three shrubs showed： Li. vicaryi〉 F. suspensa〉La. indica. [ Ch, 5 fig. 1 tab. 17 ref.]