水淹对狗牙根营养繁殖植株的生理生态学效应

Ecophysiological responses of vegetative propagule of Cynodon dactylon to simulated summer flooding

关键词:  狗牙根  营养繁殖体  光合作用  蒸腾作用  水淹

Key words:  Cynodon dactylon  vegetative propagule  photosynthesis  transpiration  flooding

摘要:

通过控制实验，测定了经过水淹处理的狗牙根营养繁殖体在恢复阶段的光合作用及其相关的生理生化指标的变化。结果显示，水淹时间对恢复阶段营养繁殖体的蒸腾作用和叶片温度的影响达到显著水平，水淹深度对该时期营养繁殖体的光合作用、气孔导度、胞间二氧化碳浓度和叶片温度有显著影响。水淹还导致了恢复期间植株叶片光合色素含量的显著变化。经过水淹的植株的各类光合色素含量以及色素总含量都显著高于对照植株，其中全淹处理的植株显著高于半淹处理的植株，叶绿素a与叶绿素b的比例也是全淹处理的植株显著高于半淹处理的植株。结果表明狗牙根营养繁殖体具有较强的恢复生长和生理活动的能力，是一种适宜于水电工程库区消落带生态恢复的物种。

Abstract:

The ecophysiological effect of summer flooding on vegetative propagules of C.dactylon was uncovered through control experiments and its photosynthesis and other related physiological parameters were determined. Results showed that vegetative propagules of C.dactylon fell into dormancy during summer when stressed by summer flooding. Flooding duration had a significant effect on transpiration and leaf temperature of the recovering vegetative propagules meanwhile flooding depth significantly affected its photosynthesis，stomatal conductance，intercellular CO2 concentration and leaf temperature. Simulated summer flooding also resulted in the significant change in photosynthetic pigment content. The photosynthetic pigment content of flooded vegetative propagules was higher than that of controls，so was the fully submerged plants than the half submerged plants. The ratio of Chla to Chlb also increased with the increase of flooding depth. It indicated that vegetative propagule of C.dactylon had a good ability to recover growth and physiological activity and was a good species that could be used in the ecological restoration of hydro fluctuation belt in hydropower projects.