摘要： 采用人工模拟干热风方法,对灌浆期冬小麦进行重度干热风(重)、轻度干热风(轻)和无干热风(CK)平行对比试验。结果发现:重度干热风对旗叶光合速率(A_n)、蒸腾速率(T_r)和气孔导度(G_s)的胁迫指数(SI)为0.88,0.68,0.83,轻度干热风对A_n、T_r和G_s的SI为0.32,0.19,0.39;在重-轻-CK 3个梯度上,G_s-A_n和G s-T_r均有极显著正相关关系;轻干热风对胞间CO₂浓度(C_i)无显著影响,重干热风下C_i显著升高。综合分析认为:轻、重干热风对灌浆期旗叶光合蒸腾均有显著抑制作用,重干热风抑制作用要显著强于轻干热风;干热风引起气孔部分闭合G_s减小是光合蒸腾受抑制的主要原因,重干热风下光合还明显受到非气孔限制;非气孔因素是导致同等干热风条件下光合受抑制程度大于蒸腾的原因。

关键词: 干旱, 干热风, 高温, 光合, 蒸腾, 小麦

Abstract: Dry-hot wind with high air temperature,low moisture and specified wind is one of weather disasters for wheat in the north of China. Photosynthesis and transpiration of flag leaf play important roles in grain-filling of wheat.Photosynthetic rate(A_n),transpiration rate(T_r),stomatal conductance(G_s),and intercellular CO₂ concentra-tion( C_i) were measured before and after sever and mild dry-hot wind generated by an experimental device. The re-sults show that:the stress indexes(SI) of A_n,T_r and G_s were 0.88,0.68 and 0.83 under sever dry-hot wind,and were 0.32,0.19 and 0.18 under mild dry-hot wind;G_s showed significant positive correlations with A_n and T_r under sever,mild,and none dry-hot wind;C_i significantly increased under sever dry-hot wind,however insignificantly var-ied under mild dry-hot wind. Some conclusions were drawn that:both photosynthesis and transpiration can be signifi-cantly stressed by dry-hot wind,and more significantly stressed by sever dry-hot wind;larger stomatal limitation with less G_s was the main cause for decreases of A_n and Trunder dry-hot wind,moreover,nonstomatal limitation showed significant influence on A_n under sever dry-hot wind;nonstomatal factors lead to the larger SI of A_n than that of T_r under the same dry-hot wind.

Key words: Drought, Dry-hot wind, High temperature, Photosynthesis, T_ranspiration, Wheat

中图分类号: 

• S512.11