| The field experiment was carried out at the Changping Experimental Station of China Agricultural University to probe into the physiological and ecological characteristics(photosynthesis and transpiration) of aerobic rice under different irrigation treatments.Making use of Licor-6400 photosynthesis measure system,the photosynthesis,transpiration and stomata conductivity were measured in every two hours from 6∶00 to 18∶00.The results showed: the diurnal variation of photosynthesis rate of aerobic rice presented "double peaks" curve at earlier development period,but showed "sole peak" curve at later period(filling stage);the diurnal variation of transpiration rate presented "sole peak" curve during the whole growth period,being consistent to air temperature change;the diurnal variation of water use efficiency took on "L" shape,namely,the maximum value appeared at 6∶00,and subsequently the value sharply descended to the minimum until 18∶00.Irrigation treatments only affected the magnitude of photosynthesis,transpiration and water use efficiency,but didn't affect the variation trend.In the 4 irrigation treatments,the water use efficiency of W2 with drought stress during earlier period and sufficient water during later period was the highest. |