Effect of Endogenous Plant Hormones on Grain Filling under Regulated Deficit Irrigation in Wheat

摘要

Under regulated deficit irrigation at different stages, the changes of endogenous hormones (ABA and ZR) in developing grain were studied to identify how hormonal levels regulated the effect of water deficit on grain filling in winter wheat. Six irrigation treatments (A, B, C, D, E, F) with water deficit imposed at different development stages were set up. When water deficit was imposed at both vegetative and reproductive stages (booting or flowering) (A, B, C treatments), grain-filling rate obviously decreased and grain-filling period was shortened. On the other hand, ABA content in developing grain was obviously higher and increased faster, whereas, ZR content and the ratio of ZR to ABA in grain were much lower and increased more slowly, compared with those under the treatments (D, E, F) of no water deficit imposed at reproductive stage. With all irrigation treatments, ZR in grain reached the peak at 7 days after flowering, then declined. Among those irrigation treatments without water deficit imposed at reproductive stage, there was no significant difference in grain yield and the irrigation treatment D with water deficit conducted at both regreening and jumping stages could be suggested as a most saving and high yield irrigation way in winter wheat.