藜水分与光合特性研究

Research on Water Character and Photosynthesis Character of Chenopodium album L.

以野生藜(Chenopodium album L.)为研究对象,在2010年6月至7月早8∶00～晚20∶00(晴天)测定其含水量、水势、净光合速率(Pn)、蒸腾速率(Tr)、大气温度(Ta)等指标。结果表明:藜同化枝含水量日变化出现两个低峰,且自由水含量相对较低,自由水/束缚水比值呈现出早晚高、午间低的现象;藜茎的水势日变化出现两个低峰,叶水势比茎小,呈单峰型,同化枝的水势为单峰型;藜蒸腾速率的日变化曲线呈M型,蒸腾速率在日变化中有"午休"现象;藜净光合速率的日变化曲线呈M型,净光合速率的日变化中有明显的"午休"现象。

From June to July in 2010, wild Chenopodium album L. taken as the studied object, its water content, water potential, net photosynthetic rate（Pn）,transpiration rate（Tr） and atmosphere temperature（T） were determined from 8∶00 am to 20∶00 pm （sunny day）. The results showed that diurnal change of water content of vegetative branch of the Chenopodium album L. presented two low peaks, the free water content lower, and the free water / bound water ratio showed higher in the morning and evening while lower in the midday;the diurnal change of the water potential of stem extant two low peaks, leaf water potential was lower than stem with a single peak, and the water potential of assimilation branch had one low peak. The diurnal change curve of transpiration rate was M-type, and obvious ＂noon break＂ phenomenon was presented; the diurnal change of net photosynthetic rate of C. album L. was also M-type, and obvious ＂noon break＂ phenomenon was presented.