不同氮素水平对营养生长期南荻植株光合特性的影响

Effects of Different Nitrogen Rates on Photosynthetic Characteristics in Vegetative Period of Triarrhena LutarioripariaL.Liu

为揭示南荻(Triarrhena lutarioriparia L.Liu)在不同氮素水平下的光合生理特性,本研究采用盆栽试验,比较了四倍体南荻在5种不同施氮水平处理下光合作用参数之间的差异。结果表明,在0～4 g/株氮素水平范围内,随着施氮量的增加,各处理净光合速率(Pn)、叶绿素含量随之增加。净光合速率较高的处理其植株的气孔导度(Gs)、蒸腾速率(Tr)也较高,而胞间二氧化碳浓度(Ci)较低。在施氮水平为4 g/株时,南荻叶片净光合速率和叶绿素含量达最大值,分别为24.47μmol/m2.s和3.64 mg/g。叶绿素含量与净光合速率呈显著正相关(r=0.892*)。不同施氮水平南荻植株光响应曲线不同,施氮可提高南荻暗呼吸速率(Rd)和光补偿点(LCP);在施氮为2 g/株和4 g/株处理时有较高的表观量子效率(AQY);在2～4 g/株氮素水平范围内,植株最大净光合速率较大。

In order to study the photosynthetic characteristics of Triarrhena Lutarioriparia L. Liu under different nitrogen rates, the difference in photosynthetic parameters was compared by pot experiment with 5 nitrogen rate treatments. Results indicated that Pn （ net photosynthetic rate） and the chlorophyll content were increased in nitrogen rate range, of 0 - 4 g/ plant. Higher G. （stomatal conductance） and Tr （transpiration rate） appeared simultaneously with higher P., while Ci （intercellular CO2 concentration） showed contrary. P, and the chlorophyll content were the highest （24. 47 μmol/m2 · s and 3. 6445 mg/g） at level of 4 g/plant nitrogen application. Significant positive correlation existed between chlorophyll content and net photosynthetic rate （ r = 0. 892 ＊ ）. The light - response curves were different under different nitrogen application rates. Rd （apparent dark respiration rate） and LCP （light compensation point） were increased after the nitrogen application. AQY （ apparent quantum yield） was higher at the level of 2 g/plant and 4 g/plant nitrogen application. P, increased in the range of 2 - 4 g/plant nitrogen application.