Abstract: Plant temperature and its relations to the micro-climate of rice canopy and the factors of irrigation water were studied under irrigation treatment(10-15 cm water layer) and CK(no water layer) using a thermo-sensitive genic male sterile(TGMS) rice,Pei′ai 64S as material.There were both value and phasic differences between the rice plant temperature and air temperature at 150 cm height.From 8:00 to 20:00,the plant temperature was lower than air temperature,whereas was close during 21:00 to next 7:00.The maximum of plant temperature appeared one hour earlier than that of air temperature,whereas both reached the minimum at 6:00.The fluctuation of plant temperature was lower than that of air temperature.At a certain height,during 6:00-13:00,the plant temperature was higher,and one hour earlier reached the maximum compared with air temperature,however,during the other time,the plant temperature was close or even a little lower than air temperature under sunny days.Contrastively,on overcast days,the plant temperature was higher than air temperature in all day,and both maximized at the same time.Plant temperature was controlled by solar radiation,and modified by cloudage and wind in the daytime.Moreover,plant temperature was mainly affected by irrigation water at night.In the present experiment,air temperature(Ta) of 29.6℃ was the critical point.WhenTa>29.6℃,irrigation water would decrease plant temperature,otherwise increase.The plant temperature and the temperature difference of water-air showed a conic relation.Rice leaf absorbs or reflects solar radiation during daytime,and countercheck the loss of heat during night time,thereby mitigating plant temperature fluctuation.By correlation analysis and coefficient simulation,two effective practical models of plant temperature were established.

Key words: rice, plant temperature, air temperature, simulation model, thermo-sensitive genic male sterility

摘要： 以温敏核不育水稻培矮64S为材料，采用10～15 cm水层灌溉处理和无水层对照，对植株温度及其与植株冠层小气候和灌溉水因子的关系作了分析。水稻植株温度与150 cm大气温度在数值和相位上均存在一定差异。8:00～20:00植株温度均明显低于大气温度，21:00～次日7:00植株温度与大气温度基本相同；日最高植株温度出现在13:00，比最高大气温度提前1 h，但日最低植株温度和最低大气温度均出现在6:00；植株温度的平均日较差比气温小。在同一高度上相比，晴天6:00～13:00植株温度比空气温度高，而且提前1 h升温，18:00～次日6:00则两者逐渐趋同或植株温度稍低；而在阴天，植株温度则全天一直高于空气温度，最高温度出现的时间也相同。植株温度白天的变化主要受太阳辐射的影响，天空状况（云量或日照时数）和风速都通过对辐射强度的调节和热量的交换而产生作用。植株温度夜间的变化主要受灌溉水的影响。在本试验条件下，日平均气温（Ta）29.6℃是灌溉水提高或降低植株温度的临界温度值，当Ta＞29.6℃时，灌溉水具有降低植株温度的作用，反之，灌溉水具有提高植株温度的作用。植株温度与水气温差符合二次曲线关系。植株冠层在白天吸收或反射太阳辐射，夜间则阻挡热量散失，对调节植株温度具有明显的缓冲效应。通过相关分析和回归拟合，建立了两个可供实用的水稻植株温度的环境模型。

关键词: 水稻, 植株温度, 气温, 模型, 温敏核不育