摘要
在人工气候室内,模拟大气干旱和土壤干旱条件,从苗木水分状况、原生质抗旱特性以及水分利用效率等三个方面,研究了2年生油松苗和侧柏苗的抗旱特性及其机理。结果表明:油松、侧柏苗木都具有较强的抗旱能力,但是,它们的抗旱机理则不相同。油松苗木以抗脱水为其抗旱特征,而侧柏苗木则以耐脱水为其抗旱特征。
The experiments was carried out under the condition imitating atmospherical and soil drought in a walk-in Growth Chamber.The characteristics and mechanism of drought resistance of 2 year old Pinus tabu-laeformis and Platycladus orientalis seedlings were studied with respect to. their water status, plasma drought tolerance and water use efficiency. The main points examined were water potential, water staturation deficit ,bound-water content, water holding ability, plasma relative permeability, photosynthesis,and transpiration. The results show that the seedling water potential becomes more negative,the transpiration rate decreases, and the net photosynthetic rate gradually declines as soil water stress develops. The results also show that their mechanism of drought resistance is somehow different. The Pinus tabulaeformis seedling is of dehydration postpon-ment: having a greater boundwater content, strong water holding ability, lower transpiration rate and an earlier closing stomata for decreasing water loss, avoiding plasma dehydration. On the other hand, the Platycladus orientalis seedling is of dehydration tolerance, raising the ability of taking in water by greatly declining seedling water potential,heavy plasma dehydration, only being subjected to slight injury, postponing close of the stomata and keeping a little transpiration and photosynthesis under severe drohght stress.
出处
《北京林业大学学报》
CAS
1988年第2期23-30,共8页
Journal of Beijing Forestry University
关键词
油松
侧柏
苗木
抗旱特性
水势
水分逆境
Pinus tabulaeformis, Platycladus orientalis, water potential, drought resistance, water stress
