干旱胁迫下不同类型野生杏光合作用比较

The Comparison of Photosynthesis in Different Types of Wild Apricot under Water Stress

【目的】以田间栽培收集于新疆伊犁地区的野生甜仁杏1号、野生甜仁杏2号、野生苦仁杏1号和野生苦仁杏2号等4种类型天山野生杏的2年生树苗为材料,持续26 d的田间自然干旱胁迫处理,研究野生杏光合作用对干旱胁迫的适应特征。【方法】对二年生野杏苗水分胁迫处理第5和26 d测定光合速率(Pn),气孔导度(Gs),细胞胞间隙CO2浓度(Ci)蒸腾速率(Tr)并计算水分利用效率(WUE),同时取样分析水势、细胞膜透性和叶绿素含量等参数。【结果】水势与膜透性的适应性变化与植物的抗逆性有关;水分胁迫第26 d净光合速率在胁迫初期的基础上下降幅度在不同类型之间有差异,下降幅度依次为:甜仁杏1号>甜仁杏2号>苦仁杏1号>苦仁杏2号。【结论】天山野生杏在水分胁迫下,净光合速率的下降是由气孔和非气孔因素共同作用的结果,气孔和非气孔因素对净光合速率下降的贡献在类型之间有差异。在野生杏叶绿素a/b比值和水分利用效率的变化与净光合速率之间有相关性。

【Objective】The field cultivated biennial seedlings of sweet kernel No. 1 and No. 2,bitter kernel No. 1 and No. 2,4 types of wild apricot（ Armeniaca vulgaris Lam.）,which were collected from Ili region of Xinjiang were used for this experiment,26 d of drought stress treatment was performed in order to investigate the adaptive traits of photosynthesis of wild apricot under water stress conditions.【Method】The 5 th and 26 th days of interception of water,the photosynthetic rate,stomatal conductance,intercellular CO2 concentration and the transpiration rate were measured,and the water use efficiency was calculated,meanwhile the water potential,cell membrane permeability and the chlorophyll contents were determined.【Result】The adaptive change of water potential and the cell membrane permeability were related to the stress resistance,the range ability of net photosynthetic rate different between the types of wild apricot,the order of range ability as：sweet kernel No. 1 〉 sweet kernel No. 2 〉 bitter kernel No. 1 〉 Bitter kernel No. 2. 【Conclusion】The decrease of net photosynthetic rate be resulted both from stomatal and non-stomatal factors in wild apricot,and the contribution of stomatal and non-stomatal to decrease in photosynthetic rate was different between the types of wild apricot. The changes of chlorophyll a / b ratio and the water use efficiency were correlated to the variability of net photosynthetic rate.