Pathogenic Races of Pyricularia oryzae Isolated from Various Rice Cultivars on the Blast Nursery and Paddy Field in Different Locations

Coordination Division, Research Policy Bureau, Rural Development Administration, Suwon 441-707, Korea(Received on August 27, 2012; Revised on November 30, 2012; Accepted on December 7, 2012)This study was conducted to investigate the association of race distribution of Pyricularia oryzae with ricecultivar and location. Races present in a given location were different in cultivars, and the races from a givencultivars were different by location. For precise study of race distribution, it needs to identify isolates byconsidering cultivation ratio and collection area. There are great differences between the resistant degree inthe upland blast nursery and on the resistant degree of the leaf blast and panical blast in the paddy field. Thenumber of virulent races in a rice cultivar was not related with the resistant degree in blast nursery or inpaddy field.Keywords : Pyricularia oryzae, Race, Rice blast