不同温度环境下灰枣光合特征日变化的研究

Study on the Photosynthetic Characteristics Diurnal Variation of Huizao under Different Temperatures

【目的】研究不同温度环境下灰枣叶片光合特征日变化规律,为灰枣栽培提供理论依据。【方法】以吐鲁番地区博斯坦乡7年生灰枣为试材,设置2个试验观测组,分别为低温晴天(日平均气温23℃)观测组W1、高温晴天(日平均气温35℃)观测组W2,利用便携式光合测定仪测定灰枣枣树的净光合速率(Pn)、蒸腾效率(Tr)、水分利用效率(WUE)、气孔导度(Gs);利用田间小气候自动气象站对灰枣园的气温(T)、大气相对湿度(RH)、光合有效辐射(PAR)等环境因子进行收集,并在此基础上采用相关分析法对其光合特征日变化规律与环境因子的关系进行定量分析。【结果】(1)两组观察试验中灰枣叶片的净光合速率日变化呈双峰曲线,在11∶00和15∶00左右出现峰值,在13∶00左右出现较低值,有明显的"光合午休现象";高温、低温环境下灰枣叶片蒸腾效率日变化差异明显;23℃环境下水分利用效率高于35℃环境下;两组观测试验气孔导度的日变化与净光合速率的日变化相似。(2)对光合参数之间相关性分析表明,23℃环境下,Pn与WUE极显著正相关(P<0.01),与T、Tr负相关;Tr与PAR极显著正相关(P<0.01),与RH负相关;WUE与T负相关;Gs与PAR、T负相关;PAR与RH负相关;RH与T极显著负相关(P<0.01)。35℃环境下,Pn与PAR、T负相关;Tr与WUE显著正相关(P<0.05),与Gs极显著正相关(P<0.01);WUE与Gs显著正相关(P<0.05),与RH负相关;PAR与RH负相关;RH与T负相关。【结论】日平均气温23℃,灰枣光合特性比较明显,净光合速率较强,水分利用效率较高,该温度有利于灰枣叶片进行光合作用。日平均气温超过35℃影响灰枣叶片的气孔导度和水分利用效率,从而影响光合速率,对光合作用产生不利影响。

【Objective】To study the photosynthesis diurnal variation of huizao under the different temperature and aims to provide the theory for planting it.【Method】The experiment used the 7 years living tree of huizao in Bernstein Township,Turpan area as the testing material,setting two observation groups,which were sunny day at low temperature W1( daily average temperature was 23℃),and sunny day at high temperature W2( daily average temperature was 35℃). Portable photosynthesis was applied to measure the net photosynthetic rate,transpiration efficiency,water use efficiency and stomatal conductance of huizao tree; Besides the automatic meteorological station was made use of to collect the temperature,relative humidity of atmosphere,and photosynthetically active radiation of jujube yards. Based on the data,the correlational analysis method was employed to analyze the correlation between photosynthetic performance and environmental factors. 【Result】1 The net photosynthetic rate of huizao blade presented bimodal curve,the crest appeared at the 11 am and 15 pm,the trough appear 13 pm,and appear the ' photosynthetic lunch break phenomenon'; There was remarkable difference transpiration efficiency between high and low temperature; the water use efficiency under low temperature exceeded the one under high temperature; the daily variation of stomatal conductance was similar to the daily variation of the net photosynthetic rate under different temperatures. 2 Analysis of the relevance between the photosynthetic parameter showed that under the low temperature,the Pn had very significantly positive correlation with WUE( P < 0. 01) and negative correlation with T and Tr. Tr had very significantly positive correlation with PAR( P < 0. 01) and negative correlation with RH; WUE had negative correlation with T; Gs had negative correlation with PAR and T; PAR had negative correlation with RH; RH had very significantly negative correlation with T( P < 0. 01). Under the high temperature,the Pn had negative correlation with PAR and T; Tr had significantly positive correlation with WUE( P < 0. 05) and had very significantly positive correlation with Gs( P < 0. 01); WUE had significantly positive correlation with Gs( P < 0.05) and negative correlation with RH; PAR had negative correlation with RH; RH had negative correlation with T. 【Conclusion】Under low temperature( daily average temperature of 23℃),the photosynthetic characters of huizao were more obvious,the Pn was stronger,the WUE was higher than others,the temperature was in favour of photosynthesis of huizao. The temperature which exceeded 35℃ would influence the Gs and WUE,thus it had negative effects on the photosynthesis of huizao.