Abstract:To characterize the phenotypic structure of Phytophthora capsici populations on pepper in Fujian, 300 isolates of P.capsici collected from different regions in Fujian were assessed based on mating type, metalaxyl response and physiological race. The results showed that 288 isolates belonged to A2 mating type with frequency of 96% and 12 isolates were A1 mating type with frequency of 4%, respectively. A2 mating type was the majority and distributed in all sampling regions. Meanwhile, 263 isolates were sensitive to metalaxyl, 28 isolates were intermediate sensitivity to metalaxyl, and 9 isolates were resistant to metalaxyl, the frequency of sensitive, intermediate and resistant isolates were 87.67%, 9.33% and 3.00%, respectively. Metalaxyl-sensitive isolates was frequently in Fujian. In addition, based on the pathogenicity on a set of four pepper differential lines, tested isolates were classified into three physiological races, and 168 isolates were physiological race 3 with the frequency of 56%, 126 isolates were physiological race 2 with the frequency of 42%, and the remaining 6 isolates were physiological race 1 with the frequency of 2%. These data demonstrated that physiological race 3 was dominant in Fujian.