不同水分灌溉下水稻光合特征分析

不同水分灌溉下早稻各处理抽穗晚期群体光合效率相差甚微,晚稻则差异显著,未灌水仅为淹灌处理的39.3％。正常灌水下水稻晴天和阴天均出现光合“午睡”现象,晴天较阴天强烈。阴天上午9:00左右和下午15:00左右光合出现主次2个峰值,晴天全天最大峰值出现在上午10:00～11:00左右,而下午峰值则出现在17:00左右。监测数据表明,空气湿度和冠层CO_2浓度是影响水稻光合速率的主导环境因子,未灌水处理的光合日变化峰值在晴天会提前出现,而阴天则近似相反,晚稻各处理晴天和阴天均以淹灌处理光合速率最大,未灌水处理最小,配灌介于其间。

Analysis on photosynthesis characteristics in rice under different irrigations

The cumulation photosynthesis effect in the condition of different irrigations on the paddy has the different results.The contrast of colony photosynthesis efficiency after heading between different irrigations in the paddy is notable but very little in the early paddy.The midday depression always appears regardless of the sunny days or cloudy days in the condition of normal irrigation.The photosynthesis reaches the peak values at 9 o'clock and 15 o'clock in the cloudy days,and at 11 o'clock and 17 o'clock in the sunshine days.Data indicate that the air humidity and the concentration of CO2 are the two dominant environmental factors affecting the photosynthesis peak value.The peak value of Tianguan appears ahead of time by the other measurements in the sunshine days,but: it has the nearly reversed result in the cloudy days.Of the four kinds of irrigation,Tianguan has the weakest photosynthesis velocity,Yanguan has the strongest,and Peiguan stands in the middle.