Studies On Spatial-temporal Dynamics Of Phytophthora Sojae Population Genetic Structure

The soybean phytophthora root rot, caused by Phytophthora sojae, is one of world important devastating disease. This disease causes approximately＄1-2billion in annual agricultural losses around the world. Planting resistant cultivars is currently the major control method for phytophthora root rot on soybean. However, the mutability of pathogens will cause the resistance loss of resistant cultivars. Studies on the population genetic structure and variation of Phytophthora sojae will help us to develop sustainable disease control strategies.Spatial-temporal dynamics of Phytophthora Sojae population genetic structure were studied based on pathotypes, dimethomorph sensitivity, and microsattlite (SSR) markers in this paper. The results showed that they were consistent between hypocotyl slit inoculation method and etiolation soybean inoculation method, and both of them get the results steady and repeatability. It showed that etiolation soybean inoculation method will be suitable for pathotypes test in the experiments. Phytophthora Sojae isolates, which collected from different regions (Heilongjiang and Fujian Xiamen, Fujian Zhangzhou), different period of infection (prophase and late period) and different source (soil and plant), were all sensitive to dimethomorph. The P. sojae isolates collected from Xiamen and Zhangzhou were more similar to each other than those from Heilongjiang province, and it showed that P. sojae isolates collected from Fujian was not come from Heilongjiang. The results also showed that virulence formula and genetic diversity of isolates collected from early-stage were more abundant than those from period. The late period population had higher evolution. Virulence formula and genetic diversity of isolates collected from soil were more abundant than those collected from lesion on soybean. The isolates collected from soil had higher evolution than those from lesion on soybean.