Abstract:

Growth and photosynthetic characteristics of rice were studied under four irrigation modes,including dry cultivation,wet cultivation,continuous flooding and intermittent irrigation,which were set to simulate the diversity of water resource situations in different areas or landforms.The results showed as follows.Rice under dry cultivation suffered drought stress,which led to few tillers,low percentage of ear bearing,short and narrow leaf,small specific leaf area,low leaf area index and photosynthetic rate,and a low yield.Wet cultivation basically sustained rice growth and the rice exhibited high percentage of ear bearing,large leaf area,high photosynthetic rate,and a high yield.Continuous flooding exerted harmful effect on rice,with its rice having low root activity,high leaf droop rate,low photosynthetic rate compared with that under wet cultivation.Intermittent irrigation showed the highest yield for its rice,with long and wide leaf,high leaf area index,and high photosynthetic rate.The result of fluorescence inducement showed that rice under dry cultivation and wet cultivation exhibited higher thermal exhaustion,while rice under intermittent irrigation and continuous flooding sent out more fluorescence to released excessive light energy.