STUDIES ON THE VIRULENCE DIFFERENTIATION OF CHESTNUT BLIGHT FUNGUS CRYPHONECTRIA PARASITICA
板栗疫病菌致病力分化的研究

According to the results of inoculations on seven Chinese chestnut varieties with nine selected strains of chestnut blight fungus obtained from five regions in Guangxi the strains could be divided into supervirulent strains, virulent strains and hypo-virulent strains, but they had no differentiation of physiologic races. The virulence in chestnut varied with different virulence types. If the mycelia of a hypo-virulent strain was mixed with the mycelia of a supervirulent strain, the later virulence could be weakened greatly. All of nine tested strains contained fungal virus RNA (dsRNA), it proved that the hypo-virulence was not controlled by dsRNA. Most Chinese chestnut varieties had high resistance to chestnut blight fugus, although there were some differences among these varieties.