The sensitivity of 113 isolates of wheat powdery mildew (Blumeria graminis f.sp.tritici) sampled from 6 provinces or cities in 2008 to temperature was tested by detached leaf segment method with setting up 5 different temperatures indoor. The results showed the mean ET50 (which represents the temperature that is required to obtain 50% of the maximum effect) of all isolates tested was 23.02℃. ET50 values of 17.70% isolates were more than 24℃. The highest and the lowest ET50 of isolates were 25.22℃ and 19.42℃, respectively. There were a certain differences for isolates sensitivity to temperature among different provinces or cites. It was also found that when temperature increased during 22-26℃, the latent period of isolates prolonged, and the latent period of different isolates was different at the same temperature, too. These results will provide a reference for the oversummering division of wheat powdery mildew, as well as the effect of climate to the disease.
