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

CLC Number: 

• S512.11