Abstract: A stomatal conduction model consisting of root water uptake model and stomatal control model under the participation of rootsourced signal ABA was developed in this paper,which considered the root water uptake effect function and root length density distribution function during root-sourced signal production.This model was used to simulate the course of maize stomatal conduction controlled by the root-sourced signal in field.The results showed that owing to the considering of the influence of root water uptake effect function and root length density distribution in soil profile,this model could more accurately depict the intensity of root water uptake,the ABA concentration produced in root system,the root ABA concentration in different soil layers and in xylem,and the controlling process of plant stomatal regulation by rootsourced ABA.

Key words: Nitrogen form, Wheat with specialized end-uses, Root system, N use efficiency