Isolating and Identifying Physiological Races of Phytophthora nicotianae in Sichuan

In order to better understand the composition and distribution of Phytophthora nicotianae (P. nicotianae) in Sichuan, 108 samples of P. nicotianae were collected from the main tobacco planting areas of Sichuan, 74 P. nicotianae isolates were obtained through isolating the samples with tissue isolation method. The isolates were further identified by TTZ color reaction method and host assay. The results showed that there existed Race 0 and Race 1 in Sichuan, which accounted for 28.38% and 71.62%, respectively; and Race 1 was in dominance. Both Race 0 and Race 1 existed in all the areas where the samples were collected.