Effect of Paclobutrazol on Leaf Senescence and Yield of Wheat

To determine the effect of the Paclobutrazo1 on wheat physiological and yield,during the wheat elongation stage,different concentration of the Paclobutrazo1 solution(0,100,200 and 400 mg/L) were sprayed on the wheat leaves,the content of chlorophyll,net photosynthetic rate,superoxide dismutase activity(SOD),catalase activity(CAT) of the flag leaf,the content of malondialdehyde(MDA),soluble protein content and the index on economic output in the seeds were measured in different periods after spraying.The results showed that proper concentrations of the Paclobutrazo1(100,200 mg/L) could delay the decrease of chlorophyll content and net photosynthetic rate,increase the SOD activity and CAT activity,and inhibit the lipid peroxidation effectually.Consequently,the spikelets and grain weight and 1 000-grain weight etc.improved significantly than that of the control without Paclobutrazo1.