Abstract: The physiological changes, including chlorophyll, malondialdehyde (MDA), Peroxidase (POD), from 22 species of landscape plants were studied under drought stress. This study also evaluated and graded their drought resistance through physiological parameters, principal components analysis and clustering analysis. The results showed that: (1) In drought gradient, the chlorophyll content of leaves showed a decreasing trend in different extent, generally, while a few showed an increasing trend; the content of MDA and relative electrical conductivity both showed an increasing trend in different extent; the POD activity of most plants showed a rising trend at first and then a decreasing trend, while a few showed a continuous increasing trend. (2) The drought tolerance of 22 plants were divided into three grades: Fagraea ceilanica, Schefflera octophylla, Osmanthus fragrans var. fragrans, Iris tectorum for grade A, drought-enduring plant; Ruellia simplex, Gardenia jasminoides, Codiaeum variegatum, Syzygium hancei, Excoecaria cochinchinen, Jasminum sambac for grade B, moderate drought-tolerance plant; Carmona microphylla, Aglaia odorata, Hibiscus rosa-sinensis, Jatropha integerrima, Ixora chinensis, Allamanda schottii, Duranta erecta, Loropetalum chinense var. rubrum, Lagerstroemia indica, Cyperus involucratus, Rosa chinensis var. minim, Hydrocotyle chinensis for grade C, drought-intolerant plant.

Key words: landscape plants, drought resistance, comprehensive evaluation, clustering analysis

摘要： 以华南地区22种常见园林植物为研究对象，研究人工模拟干旱胁迫环境对植物叶片叶绿素、丙二醛、过氧化物酶、相对电导率等生理指标的影响，通过主成分分析、聚类分析对22种植物耐旱性进行综合分析评价和耐旱等级划分。结果表明：(1) 在干旱梯度胁迫期间，植物叶片的叶绿素含量总体上呈不同程度的下降趋势，少数呈上升趋势，丙二醛含量和相对电导率均呈不同程度的上升趋势，多数植物过氧化物酶活性呈不同程度先升后降趋势，少数呈持续上升趋势。(2) 22种植物耐旱性分为3个等级：A级强耐旱植物4种，包括灰莉(Fagraea ceilanica)、鸭脚木(Schefflera octophylla)、桂花(Osmanthus fragrans var. fragrans)、鸢尾(Iris tectorum)；B级中耐旱植物6种，包括翠芦莉(Ruellia simplex)、栀子花(Gardenia jasminoides)、变叶木(Codiaeum variegatum)、红车(Syzygium hancei)、红背桂(Excoecaria cochinchinen)、茉莉花(Jasminum sambac)；C级不耐旱植物12种，包括福建茶(Carmona microphylla)、米仔兰(Aglaia odorata)、大红花(Hibiscus rosa-sinensis)、琴叶珊瑚(Jatropha integerrima)、龙船花(Ixora chinensis)、黄蝉(Allamanda schottii)、假连翘(Duranta erecta)、红檵木(Loropetalum chinense var. rubrum)、紫薇(Lagerstroemia indica)、风车草(Cyperus involucratus)、小花月季(Rosa chinensis var. minim)、铜钱草(Hydrocotyle chinensis)。

关键词: 园林植物, 耐旱性, 综合评价, 聚类分析