干旱胁迫对香蒲生长和叶绿素荧光参数的影响

采用野外调查方法,研究了不同土壤含水量条件下香蒲植株的形态、生物量、叶绿素含量和叶绿素荧光参数的变化。结果表明：（1）土壤含水量对香蒲株高影响显著,轻度、中度和重度干旱处理香蒲株高分别下降为对照（土壤水分始终饱和）的90.90%、68.19%和63.64%。（2）香蒲茎直径、叶长、叶宽和叶绿素含量均随土壤含水量的降低而呈递减趋势,枯叶率却明显增加。（3）不同土壤含水量条件下香蒲密度和生物量差异均达显著水平（P〈0.05）。轻度、中度和重度干旱组香蒲密度分别比对照下降41.67%、53.33%和66.67%;而对照香蒲单株生物量分别为轻度、中度和重度干旱组的2.25、5.54和7.45倍。（4）香蒲叶片最大光量子产量（Fv/Fm）和最大相对电子传递速率（Re,t,max）随土壤含水量的减少而明显降低。干旱降低了香蒲叶片光系统Ⅱ（PSⅡ）的光化学效率,抑制了香蒲的生长。

Effects of Drought Stress on Growth and Chlorophyll Fluorescence Parameters of Typha orientalis

Field surveys were carried out to explore effects of soil moisture on morphology,biomass,chlorophyll content and chlorophyll fluorescence parameters of Typha orientalis.Results show that（1） soil water content significantly affected plant height of T.orientalis,which was 90.90%,68.19% and 63.64% of that in the control group（soil water saturation）,when the plants were exposed to light,moderate and heavy drought stress,respectively;（2） stem diameter,leaf length,leaf width and chlorophyll content in the leaf decreased with the decreasing soil moisture content,while percentage of withered leaves significantly increased;（3） treatments different in soil moisture content differed sharply（P0.05） in density and biomass of T.orientalis,and density of the plants decreased by 41.67%,53.33% and 66.67% in the treatment of light,moderate and heavy drought stress,respectively,while biomass of a single plant in the control was 2.25,5.54 and 7.45 times that in the treatment of light,moderate and heavy drought stress,respectively;and（4） the maximum quantum yield of the leaves（Fv/Fm） and maximum electron transport rate（Re,t,max） decreased significantly with the decreasing soil moisture content;and drought reduced photochemical efficiency of the PSⅡ of leaves,thus inhibiting the growth of T.orientalis.