高温胁迫下高羊茅草坪草生理特性研究

从美国引进的39个高羊茅草坪草种分成了5个生态类型,在1999—2000年从每类中找出一个具有典型性状的草种,测定其周年草坪坪质表现、根系活力、叶片可溶性糖含量变化,同时测定各类草种在高温胁迫下保护酶活性与质膜透性的变化。结果表明,根系活力及可溶性糖含量在一定程度上影响着草坪坪质的周年变化。同时,草坪草叶片MDA含量的增长率和草坪草叶片的质膜透性增长率具有显著的正相关效应。在40℃高温胁迫下,草坪草叶片SOD与POD相对活性和MDA含量的增长率及PMP增长率具有显著的负相关效应,5个草种对高温的抗性能力大小顺序是:Gooden>Regi ment>Tomahawk>SR-8210>Brandy。在此基础上,最后对草坪草抗性的准确快速检测方法进行了讨论。

Physiological response to heat stress in tall fescue turfgrasses

Thirty-nine tall fescue varieties introduced from America were devided into five ecotypes, from which five cultivars were collected for testing the changes of turf quality, root activity, soluble sugar content around years,meanwhile antioxidant enzyme activity, lipid proxidation etc under heat stress conditions were tested too in 1999-2000.The results indicated that changes of root activity and content of soluble sugar in the leaves were to some extent responsible for adjusting the stress-resistance in heat stresses, It implied that the two parameters had a great effect on the turf quality of tall fescue around the year.It was also indicated that the increasing rate of MDA content was significantly positively correlated with the changes of electrolyte leakage in the leaves of turf grass. When exposed to 40 ℃ heat stress,the relative activities of superoxide dismutase(SOD) and peroxidase(POD) in the leaf of turf cultivars concerned were significantly negatively correlated with malonaldehyde(MDA) and electrolyte leakage.Based on the index of active oxygen and electrolyte leakage, the ability of heat tolerance in the five ecotypes of tall fescue was in order:Gooden＞Regiment＞Tomahawk＞SR-8210＞Brandy. Finally, a rapid accurate laboratory procedure of measuring turf grass tolerance to heat was also disscussed.