Identification of Physiological Races of Pyricularia oryae in Heilongjiang Province of China from 2007 to 2011

In order to clear the composition and distribution of physiological races of Pyricularia oryae in Heilongjiang Province, 299 single spore isolates of P. oryae collected from five rice regions （30 cities, counties or farms） in Heilongiiang Province form 2007 to 2011 were identified by seven differential varieties in Chi- na, and a total of seven groups with 31 physiological races had been identified. The results showed that ZA, ZD and ZB groups were the dominant groups in Hei- longjiang Province, with the occurrence frequencies of 34.8%, 31.1% and 16.1%, respectively. ZD5 was the dominant race with the oeeurrence frequency of 17.1% ; followed by ZA49 and ZD1 , with the occurrence frequencies of 13.7% and 10.7% , respectively. The types and compositions of physiological races of P. oryae varied with rice regions.