Abstract: HYSPLIT-4 deposition model was employed to numerically simulate the 10 years urediniospore transmission of wheat stripe rust in its Aba and Longnan over-summering areas. The data were processed by the method of overlay calculation with ArcGIS 9, and thus, the probability distribution of the urediniospore deposition could be predicted. The results showed that if wind fields were favorable, the urediniospore in Longnan area could transmit to the winter wheat cropping areas in parts of Huanghuai region, middle and lower Yangtze River basin, and North China Plain, and would affect the rust infection on the autumn seedlings there, whereas the urediniospore transmission from Aba area had little influence on the infection. Based on the results of numerical simulation, it was supposed that the over-summering area of wheat stripe rust in Longnan could determine the infection of autumn seedlings in Guanzhong area directly. Both Aba and Longnan areas could provide a great deal of urediniospore to the winter propagating area of Sichuan basin and southern Shanxi. There was a frequent transmission of wheat stripe rust urediniospore between Aba and Longnan areas. Our study further confirmed the previous judgment about the continuum of the over-summering area of wheat stripe rust pathogen in Northwest China and Northwest Sichuan.

Key words: Soil oxidoreductase, Kinetics, Properties