By inoculation on apple with 2 wild canker pathogens and their nitrite mutant isolations and heterokaryotic isolations,the pathogenicity was got and analyzed by variance and multiple comparisons.

• 以2株溃疡病菌株及其亚硝酸盐诱变菌株、异核体菌株接种苹果进行致病性测定,经方差分析和多重比较表明,溃疡病菌致病力变异可由亚硝酸盐诱变、异核体产生。