Abstract: The result of five years’ survey on the physiologic races of P. recondita f. sp. tritici indicated that races 1 , 2 , 3 , 38 and Lovrin 10 race group which was virulent to important sources of resistance were prevalent ones. Race 2 remained stable, race 1 slightly increased, race 3 and 38 slightly decreased, and Lovrin 10 race group incrcaced rapidly from 18.33% in 1985-1986 to 57.65% in 1989-1990 in frequency.Besides using the traditional method to monitor the races, effert was made to improve the viewpoint and method of research. The taxonomic point of view of distinguishing the races was abandoned and a view of interorgani-smal genetics was adopted to study host-parasite interaction. Seven of 8 differential hosts established by Chinese workers were replanced by 8 sources of resistance and cultivars which were important in relation to wheat production as well as breeding program. Metheds of virulence frequency and virulence association were used to analyze the interaction of wheat cultivars and the population of pathogen. Virulence frequency method revealed that some important sources of resistance such as Lovrin 10, Lovrin 13 and Predgornaja 2 were not ideal resistance parents for breeding. The virulence association method seemed to be useful in designing variety deployment rationally.

Key words: Wheat, Puccinia recondita f. sp. tritici, Breeding for rust-resistance, Physiologic race