作物内禀水分利用效率变化

Variation of Intrinsic Water Use Efficiency for Crop

为探究不同作物类型内禀水分利用效率(IWUE)之间的区别及其环境影响因素,本研究以春玉米科河28和春小麦定西新24为试验材料,通过桶栽和小区试验,设置水分充足和干旱胁迫2个处理,观测玉米、小麦在不同水分和不同气象条件下的叶片光合生理过程并收集文献资料,分析比较C3和C4作物之间,以及不同环境条件下相同作物IWUE的变化特征及气孔导度模型斜率。结果表明,C4作物玉米较C3作物小麦具有更高的IWUE;有利的环境条件下,小麦IWUE较低,而不利的环境条件下,小麦倾向于提高IWUE;生长在湿润区的C3作物IWUE较低,而半干旱区的C3作物IWUE较高;小麦的气孔导度模型斜率高于玉米,同时不利的环境条件及干燥的气候条件下,作物倾向于降低气孔导度模型斜率。综上,作物气孔调节方式具有优化利用水分的功能,在不利的环境条件下,作物的水分利用方式倾向于保守,从而在较小的水分消耗下,获得最大的产出。本研究结果为区域作物品种选择及布局提供了参考依据。

In order to explore the difference of intrinsic water use efficiency(IWUE)between different crop types and its environmental impact factors,Kehe28 for maize and Dingxixin24 for wheat were used as experimental materials,through the barrel and plot test,the two set enough moisture and drought stress treatment,observation of corn,wheat in different water content and photosynthetic physiological processes under different meteorological conditions and literature information collection,analysis and comparison between C3 and C4 plants,under different environmental conditions and characteristics of the same crop IWUE of slope and stomatal conductance model.The results showed that C4 corn had higher IWUE than C3 wheat.Under favorable environmental conditions,the IWUE of wheat was lower,while under unfavorable environmental conditions,wheat tended to increase the IWUE.Meanwhile,C3 crop growing in humid climate had lower IWUE than that growing in semi-arid climate.The slope of stomatal conductance model of maize was higher than wheat.Additionally,under stressed conditions and semi-arid climate,crops tend to reduce the slope of stomatal conductance model.In conclusion,this research indicates that stomatal conductance of crop could regulate its aperture to maximize water use.Crops tend to conserve water use under stressed conditions,whereas it consumes little water as much as possible under optimal condition to maximize assimilation.The results could provide a basis for crop variety selection and allocation in a research area.