Abstract: The physiological response and performance were investigated and evaluated for 18 Kentucky bluegrass turfgrasses by exposing them to simultaneous drought and heat stress through withholding irrigation for 21 d until complete leaf wilting of the plants.During the stress period,turf quality(TQ),relative water content(RWC),electrolyte leakage(EL),leaf wilting(LW),superoxide dismutase(SOD),catalase(CAT) and malondialdehyde(MDA) were determined in 3-d intervals.In summary,simultaneous drought and heat stresses induced oxidative injury in all cultivars,as demonstrated by the reduction in antioxidant enzymes and increase in lipid peroxidation.Meanwhile it caused TQ and RWC to decline,while EL and LW to increase with proceeding of the treatment.Through the hierarchical cluster analysis,Midnight,Rugby II,Nublue,Impact,Bluechip,and Park were in the high resistance group;Ronde,Conni,Blue moon,Merit,Odyssey,Nassau,and Nuglade were in the moderate resistance group;Award,Prize, Newport,Celle,and Campus were in the low resistance group.These results would facilitate the selection of drought and heat resistant turfgrasses for drought areas.

Key words: Kentucky bluegrass, Drought and heat resistance, Physiological response, Quality of lawn, Evaluation

摘要： 研究18个早熟禾(kentucky bluegrass)品种在干热胁迫下的生理反应并给予评价。将18个早熟禾品种干热胁迫21 d,每隔3 d评定草坪质量(TQ)、叶片萎蔫率(LW),测定叶片相对电导率(EL)、叶片相对含水量(RWC)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量的变化。结果显示:随着干热胁迫天数的增加,草坪质量、叶片相对含水量、超氧化物歧化酶和过氧化氢酶的活性都明显下降,而叶片萎蔫率、叶片相对电导率和丙二醛的含量却明显上升。经层次聚类分析,18个品种的抗旱抗热性可分为3大类,其中午夜(Midnight)、橄榄球2号(Rugby)、纽布鲁(Nublue)、浪潮(I mpact)、抢手股(Bluechip)、公园(Park)为高抗旱抗热类群;诺德(Ronde)、康尼(Conni)、蓝月(Blue moon)、优异(Merit)、史诗(Odyssey)、纳苏(Nassau)和新哥来德(Nuglade)为中抗旱抗热类群;奖品(Award)、奖金(Prize)、新港(Newport)、塞尼(Celle)和校园(Campus)为低抗旱抗热类群。该研究旨在为选育抗旱抗热草坪草种提供理论依据。

关键词: 草地早熟禾, 抗旱抗热, 生理反应, 坪用质量, 评价