摘要
5种冷地型草坪草离体叶片在骤然高温干旱（45℃不供水）条件下,细胞外渗液电导率极显著地高于在单因子高温（45℃供水）和单因子干旱（25℃不供水）条件下的电导率,后两者又极显著地高于对照条件（25℃供水）下的电导率。单因子高温和单因子干旱对细胞膜的伤害是显著的,高温和干旱的共同作用对细胞膜的伤害更大。夏季高温干旱应是造成冷地型草坪草在上海越夏困难的主要原因之一。供试材料在高温、干旱条件下,电导率最高的均为匍匐翦股颖Bent,细叶羊茅Southport,两者与其他材料间有显著差异,其次为多年生黑麦草新品系上农PRG—2和草地早熟禾Nassau,最低的为多年生黑麦草新品系上农PRG—1、高羊茅Houndog和草地早熟禾Wabash。电导率高的材料在田间的越夏表现也最差。不耐热的材料也不耐旱。本测试系统中的电导率可作为鉴定冷地型草坪草耐热、耐旱性的指标。
Tht isolated leaves of 5 species of cool - season turf grass were used as materials. The electric conductivity (EC) of cellular exudate under either high temperature or drought stress was significantly higher than that under optimal condition. EC under both high temperature and drought stress was significantly higher than that under either high temperature or dronght stress. Although either heat or drought stress could increase the relative membrane permability of the leaves it was very likely that heat and drought combined together were responsablefor the growth inhibition or the death of the grasses in summer in Shanghai suburb. Agroslis pulustrin CV. Bent and Festuca rubra (xnnmu.ta.te CV. Soulhport had the highest EC under either heat or drought stress, ljuliuin prenne Shangnong PRG-2 and Poa pratcnsis CV. Nassau the next. Lolium prenne Shangnong PRG- 1 , Fes-fucu arundiacea CV. Houndog and Poa prattnsis CV. Wabash the lowermost. The materials with lower EC were more tolerant to the stresses, while those with higher EC were more suceptible to the stresses in the field expen ment. EC in this test system could be a gcxxl index to identify the grasses in dynamics of the stress tolerance.
关键词
冷地型
草坪草
耐热性
耐旱性
电导率
Gool- season turf grass
Heat tolerance
Drought tolerance
Electric conductivity
