The genetic structure of Alternaria alternata (Fries) Keissler was influenced by genetic background of host cultivar, and the genetic structure of isolates from different host cultivar was different.

• 赤星病菌的遗传结构也随寄主品种（基因型）的不同而表现出一定的差异，寄主品种的遗传背景影响着赤星病菌的遗传结构。