Effects of Regulated Deficit Irrigation on Photosynthesis of High-yield Dwarf Wheat Cultivar

Abstract

【Objective】 Regulated deficit irrigation is an improved irrigation technology to sustain crop production in regions where freshwater resources are not abundant. This paper is to investigate the effect of deficit irrigation on photosynthesis of high-yield dwarf wheat cultivars. 【Method】 Pot experiments were conducted using three high-yield dwarf wheat cultivars: Bainong 207 (BN207), Bainong 307 (BN307), and Bainong 607 (BN607). For each cultivar, moderate regulated deficit irrigation was imposed at the seedling-winter period, jointing-beading, and flowering-filling stages (W1), or at the seedling-winter period and middle flowering-filling stage (W2), or at seedling-winter period and middle jointing-beading stage. The control (CK) was sufficient irrigation. In each treatment, we measured the photosynthetic rate (Pn) and chlorophyll fluorescence kinetic parameters of the leaves. 【Result】 Compared with CK, W3 significantly increased yield, biomass, SPAD values, and photochemical activity of all three cultivars, as opposed to W1 which reduced all these traits. The impact of the deficit irrigation on photosynthesis varied with cultivars, with BN207 showing resistance to limitations in photosynthetic electron transfer under long-term regulated deficit irrigation. Moderate regulated deficit irrigation at the early growth stage of BN607 enhanced its response to water deficit in the late growth stage. Deficit irrigation at the seedling-winter period and jointing - heading stage increased Pn of BN307. 【Conclusion】 Among the treatments we compared, W3 was optimal for achieving both high yield and photosynthesis of the three wheat cultivars investigated in this paper.

Keywords

• regulated deficit irrigation
• biomass
• chlorophyll fluorescence kinetic parameters
• ojip curves