增温和推迟播种对冬小麦生长和产量的影响的大田实验研究

The trends of daily maximum & minimum temperature in global warming indicated that the daily minimum temperature (Tmin) has risen more than twice as fast as the daily maximum temperature (Tmax) during the 20th Century.It indicated that the daily mean maximum and minimum temperatures rising were asymmetry. Most researchers have focused on how the crops respond to daily mean temperature, whereas few controlled experiments were carried out to investigate how the crops respond to the asymmetric trends of daily maximum and minimum temperature increase,which was the main trend in the climate warming. At the same time, the impact of winter wheat sowing date postponed (which is an effective measure for winter wheat to adapt to climate warming) on wheat production has not been reported. This project would concentrate on the core issue of winter wheat response to the asymmetric warming by using infrared heater to control the warming. Two treatments of current sowing and postpone sowing would be set, each treatment set three kinds of warming, i.e. the night warming, day&ninght warming and not warming in growth duration. The observations and measurements of phenological, yield, photosynthesis / respiration and environmental parameters would be carry out in growth duration. It would be find out that the impact of asymmetry warming on winter wheat growth and development, grain quality, physiological parameters and yield. It would be clarify how different warming may affect the growth and development, photosynthesis / respiration, thereby affecting the winter wheat yield and grain quality. It would reveal the physiological mechanisms that how the sowing date postponed could adapt to climate warming.

气候变暖背景下的气温升高具有非对称性特征，即日最低温增温幅度远大于日最高温增温幅度。以往研究多集中于日平均温度对冬小麦生长的影响，未考虑夜间和日间温度对冬小麦的生理效应不同；同时，未来升温情景下冬小麦播种期推迟对小麦产量影响的实验研究还未见报道。本项目围绕非对称性增温影响这一核心问题，以冬小麦为对象，采用红外辐射器控制增温，分现行播种期和推迟播种期2个处理，每个处理设置夜间增温、全天增温和不增温3种增温方式，观测冬小麦整个生育期的生长发育、产量及籽粒品质，同时测定其环境参数和光合/呼吸作用。研究两种播种期下，日最低气温升高和日最高气温升高对冬小麦生长发育、籽粒品质、生理参数和产量的影响的差异；阐明日最低气温和日最高气温如何通过影响冬小麦生长发育、光合/呼吸，进而影响冬小麦产量和籽粒品质；揭示推迟播种在减缓增温对冬小麦生长影响中的作用和生理机制，为冬小麦适应气候变暖提供科学依据。

气候变暖背景下的气温升高具有非对称性特征，即日最低温增温幅度远大于日最高温增温幅度。以往研究多集中于日平均温度对冬小麦生长的影响，未考虑夜间和日间温度对冬小麦的生理效应不同；同时，未来升温情景下冬小麦播种期推迟对小麦产量影响的实验研究还未见报道。本项目围绕非对称性增温影响这一核心问题，以冬小麦为对象，采用红外辐射器控制增温，分现行播种期和推迟播种期2个处理，每个处理设置夜间增温、日间增温、全天增温和不增温4种增温方式，观测冬小麦整个生育期的生长发育、产量及籽粒品质，同时测定其环境参数；实验进行了3年。研究得出：日最高和日最低温升高均导致作物发育期缩短，越冬期前的生育期周期延长，越冬期大幅度缩短，冬后各个发育期提前，但越冬期后发育期天数并未减少，全生育期增温，无论是最低气温升高还是最高气温升高都大大缩短越冬期，而越冬期以外的活动发育期并没有缩短，同时冬后各个发育期提前，导致其遭受高温的风险并没有因为增温而增加，也就是增温并未增加冬小麦遭受高温的风险。所以，增温最终没有导致冬小麦减产，而推迟播种可以减少冬前分蘖数，减少无效分蘖，对增产有利。同时本研究得出，增温导致冬小麦氨基酸和粗蛋白含量增加，对提高小麦品质有利。研究完成了既定的研究目标。. 根据进一步发现的科学问题，又进一步开展了一些延伸研究：设置安装了小型蒸发皿，分析了未来增温对冬小麦产量和蒸发散的可能影响；研究了增温条件下的土壤碳的变化；研究也进一步延伸研究了气候变化的对植被的影响在区域尺度上如何通过遥感来准确分析。. 本研究对于气候变暖对冬小麦影响做了系统研究，该研究成果反映了小麦响应气候变暖的机制，为小麦适应气候变化提供了科学依据。.