The Change of POD and PPO Activity and Isozyme in Wheat Varieties with Different Resistance to Wheat Powdery Mildew before or after Inoculation

Used Colorimetry and polypropylene amic gel electrophoresis(PAGE) to comparatively study the activity and isozyme of peroxidase(POD) and polyphenoloxidase(PPO) in three wheat varieties with different resistance after inoculation,Activity of peroxidase(POD) and polyphenoloxidase(PPO) showed:immune had highest POD activity before inoculation in the three varieties,and POD activity of the three varieties all appeared increasing first and then decreasing.There were no significant differences in PPO activity before inoculation,But the time of the activity peak to show up diffdrent obviously.immune,moderate and susceptible varieties showed the highest PPO activity respectively 1 day,2 days and 3 days after inoculation.Isoenzyme electrophoresis of these samples showed that difference occurred in activity of immune,moderate and susceptible POD isozyme bands occurred increased or decreased.But,PPO isozyme bands occurred diffdrent obviously in activity and numbers.The result suggested that POD and PPO may be close related with plant against Blumeria graminis f.sp.tritici.