摘要
为了探讨凝结水对植物生长的作用,该文研究了干旱处理下模拟凝结水对羊草(Leymus chinensis)和冰草(Agropyron cristatum)生理性状和叶片表面结构的影响。试验设计了干旱无凝结水、干旱每周发生3次和5次凝结水以及正常浇水不发生凝结水4个处理,通过超声波加湿器模拟凝结水的发生,研究凝结水对两种植物叶片相对含水量、水势、净光合速率、水分利用效率、生物量以及叶片表面结构等的影响。结果表明:凝结水显著增加了干旱胁迫下两种植物的叶片相对含水量和水势(p<0.05);凝结水显著提高了冰草的净光合速率、气孔导度与蒸腾速率(p<0.05);而羊草的气孔导度和蒸腾速率随凝结水的变化不明显。羊草和冰草的地上生物量和根系生物量随凝结水的发生有增加的趋势,但是各处理间差异不显著。凝结水降低了羊草和冰草黄叶数与总叶数的比值,这表明凝结水对干旱胁迫下植物叶片表面结构遭到的破损有一定的保护和修复作用。该研究证实羊草和冰草的叶片可以吸收凝结水,并对其光合作用、水分生理以及生长具有正效应。
Aims To investigate the effects of dew on plants, we conducted the experiment to determine the physiological characteristics and leaf structures of Leymus chinensis and Agropyron cristatum in response to increasing dew under drought stress. Methods Four treatments (no dew, three times dew and five times dew per week under drought stress, and well-watering) were designed to examine leaf relative water content, water potential, net photosynthetic rate, water use efficiency, biomass, and leaf structures ofL. chinensis and A. cristatum. Important findings There was a significant increase in the relative water content and water potential by simulated dew increase for two plants species under drought stress (p 〈 0.05). For A. cristatum, simulated dew increase significantly enhanced the net photosynthetic rate, stomatal conductance, and transpiration rate of plants under drought stress (p 〈 0.05). On the other hand, there was no significant difference in the stomatal conductance and transpiration rate for L. chinensis among treatments. Simulated dew increase improved the aboveground biomass and root biomass of two species. The ratio of yellow leaves to the total leaves was decreased by simulated dew increase for two species. Dew increase also protected leaf structures against the drought stress, suggesting that the dew increase can slow down the death process of leaves resulted from drought stress. Therefore, the study demon- strated that dew increased the available water for the leaves of L. chinensis and A. cristatum grown in the drought stress and thus had positive effects on the photosynthesis, water physiology and plant development.
出处
《植物生态学报》
CAS
CSCD
北大核心
2017年第11期1199-1207,共9页
Chinese Journal of Plant Ecology
基金
国家自然科学基金(41371056)
关键词
凝结水
羊草
冰草
叶片表面结构
干旱胁迫
dew
Leymus chinensis
Agropyron cristatum
leaf structure
drought stress