Abstract: 21 tall fescue cultivars were treated under simultaneous drought and heat stress in rain-shading greenhouse.Turfgrass quality was evaluated and leaf relative electrolyte leakage,relative water content,superoxide dismutase,catalase activity,and malondialdehyde content were measured.Results indicate that turfgrass quality,relative water content,superoxide dismutase,and catalase activity of each cultiva showed a decreasing trend,while leaf relative electrolyte leakage and malondialdehyde content showed an increasing trend.Moreover,the decreasing amount of relative water content,turfgrass quality,superoxide dismutase,and catalase activity and the increasing amount of leaf relative electrolyte leakage,and malondialdehyde content for Pixie,Tomcat,Fire phoenix,Ruby,Houndog V,Mustang Ⅱ,and Arid Ⅲ were lower(P<0.05)than those for Avalon,Apache,Arabia,and Triple yield,which suggest that the drought and heat stresses caused heavier injury to Avalon,Apache,Arabia,and Triple yield than other tall fescue cultivars.Through hierarchical clustering analysis,21 tall fescue cultivars were clustered into three drought and heat resistance grades.Pixie,Tomcat,Fire phoenix,Ruby,Houndog V,Mustang Ⅱ,and Arid Ⅲ were clustered in the relative drought and heat resistance group;Crossfire Ⅱ,Tulsa,Bingo,Barlexas,Olga,Gooden,Watchdog,Jaguar Ⅲ,Safari,and Quest were the moderate drought and heat resistance group;Avalon,Apache,Arabia,and Triple yield were the low drought and heat resistance group.The results of the study will provide the theoretical evidence for turfgrass screening and introduction in arid regions.

Key words: Tall fescue, Drought resistance, Heat resistance, Physiological response, Hierarchical clustering analysis

摘要： 在遮雨温室对21个高羊茅(Festuca arundinacea Schreb.)品种进行高温干旱(干热)胁迫处理,观测草坪质量,叶片相对电导率,叶片相对含水量,超氧化物歧化酶活性,过氧化氢酶活性和丙二醛含量的变化。结果表明,各品种的草坪质量,叶片相对含水量,超氧化物歧化酶活性,过氧化氢酶活性均呈下降趋势,叶片相对电导率和丙二醛含量呈上升趋势。其中,贝克、汤凯、火凤凰、红宝石、猎狗5号、野马二代、艾瑞3号的叶片相对含水量,草坪质量,超氧化物歧化酶和过氧化氢酶活性下降幅度显著低于快乐岛、阿帕奇、阿拉比亚、三丰(P<0.05),其叶片相对电导率和丙二醛含量上升幅度也较低,说明干热胁迫对快乐岛、阿帕奇、阿拉比亚、三丰的伤害较其他品种大。层次聚类分析后,高羊茅21个品种大致被分为3个抗旱抗热级别,即贝克、汤凯、火凤凰、红宝石、猎狗5号、野马二代、艾瑞3号为相对抗旱抗热类群,交战2号、特飒、滨狗、凌志、澳格、佳美、警犬,美洲豹3号、沙漠王子、追寻者为中等抗旱抗热类群,快乐岛、阿帕奇、阿拉比亚、三丰为相对敏感类群。

关键词: 高羊茅, 抗旱, 抗热, 生理反应, 层次聚类分析