增氧-控水灌溉对水稻生理生长特性及产量的影响OACSTPCD

[Objective]Soil anaerobicity is a common abiotic stress in fine-textured soils that adversely affects crop growth.Aerated irrigation,achieved by adding air bubbles to irrigation water,is a technique to mitigate soil anaerobicity.This study investigates the effect of regulated aerated irrigation on rice growth,physiological traits at different growth stages,as well as grain yield.[Method]The experiment was conducted in pots using the Zhongzao 39 rice variety as model plant.The controlled irrigation was implemented by keeping soil moisture at 80%-100%(T1)or 60%-80%(T3)of the field capacity during late-tillering stage;at 80%-100%at late-tillering and booting stage(T2);at 60%-80%during late-tillering stage and 80%-100%during booting stage(T4);at 80%-100%during middle and late tillering stages(T5),at 80%-100%from middle tillering stage to booting stage(T6),at 80%-100%during mid-tillering stage and 60%-80%during late tillering stage(T7),at 80%-100%during mid-tillering and booting stages and 60%-80%during later tillering stage.During non-controlled stages,all treatments kept a thin water layer at the depth of 0-30 cm on the soil surface.The control(CK)was conventional flooding irrigation by keeping a 0-30 cm of water layer on the soil surface.For each treatment,we measured abscisic acid(ABA),peroxidase activity(POD),pollen viability,OsFKF1 gene expression and grain yield.[Result]Compared with CK,the treatments significantly increased pollen viability,OsFKF1 expression at the heading and flowering stages,and grain yield.T3,T2 and T8 achieved the highest pollen viability(83.28%),OsFKF1 expression(2.96),and grain yield(83.908 g/plant),respectively.ABA activity in roots and leaves,and POD activity in leaves,at the mid-tillering stage differed significantly between treatments.Compared with CK,the treatments reduced ABA in roots at the mid-tillering stage by 16.73%-23.69%and POD activity in leaves at the late-tillering stage by 19.91%-66.70%;conversely,they increased ABA in roots at the booting stage by 1.37%-63.52%.At the mid-tillering stage,T1—T4 reduced POD activity in roots by 70.36%-71.55%,whereas T5—T8 increased POD activity in roots by 2.53%-7.00%.Multiple linear regression analysis showed that the treatments increased ABA in roots at the late-tillering stage,reduced ABA in leaves at the late-tillering and booting stages,and decreased POD activity in leaves at the mid-tillering and late-tillering stages.These enhanced pollen viability and OsFKF1 gene expression at the heading and flowering stages,thereby increasing grain yield.[Conclusion]Among all treatments,T3 was the most effective in regulating ABA and POD,enhancing pollen viability,and improving rice grain yield,which reached 82.18 g/plant.