高温胁迫对新疆榛光合参数和叶绿素荧光特性的影响

在5个温度梯度处理下,研究高温胁迫对4种新疆榛光合参数和叶绿素荧光特性的影响.结果表明:随着温度从25℃持续升高至45℃,新疆榛叶片的净光合速率、气孔导度、胞间CO2浓度、水分利用效率和光能利用效率逐渐降低,且在35～ 45℃之间降幅最大；光系统Ⅱ的实际光化学效率、电子传递速率和光化学猝灭系数随温度的升高缓慢上升,至35℃后急速下降；蒸腾耗水和热耗散随温度的升高而增大.4种新疆榛品种中,新榛3号的光合作用对高温的耐受力较高,属耐热性品种.

Effects of high temperature stress on photosynthetic parameters and chlorophyll fluorescence characteristics of Xinjiang hybrid hazels

With five temperature gradient treatments,this paper studied the effects of high temperature stress on the photosynthetic parameters and chlorophyll fluorescence characteristics of four Xinjiang hybrid hazels.When the temperature gradually raised from 25 ℃ to 45 ℃,the net photosynthetic rate,stomatal conductance,intercellular CO2 concentration,water use efficiency and light use efficiency of the hybrid hazels decreased gradually,and the decrement was the largest at 35 ℃-45 ℃.The actual photochemical efficiency of photosystem Ⅱ,electron transport rate,and photochemical quenching coefficient increased slowly with increasing temperature,but decreased sharply when the temperature was raised to >35 ℃.The water consumption for transpiration and the heat dissipation also increased with increasing temperature.Among the four hybrid hazels,Xinzhen No.3 had higher tolerance against high temperature in photosynthesis,belonging to heat-resistant cultivar.