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1996～1998 年对胶东地区4 县 (市) 苹果斑点落叶病标样进行病原分离培养及致病性测定, 获得了Alternaria alternata f. sp. m ali的2 个不同菌系A1、A2。在PDA 培养基上, A1 菌落正面墨绿色, 气生菌丝很少, 大量产孢, 分生孢子大小为17.1～49.0 μm ×7.3～14.7 μm ; A2 菌落正面灰白色, 气生菌丝旺盛, 产孢量少, 一般仅为前者的1/5 左右, 分生孢子大小为29.4～63.7 μm ×12.5～22.1 μm , 链生、喙长的孢子比较多见。A2 致病性显著强于A1。田间不规则大型枯斑多由A2 所致。2个菌系生长发育的最适温度分别为30 ℃和28 ℃, 最适pH 均为7, 葡萄糖与蔗糖为最佳碳源, 硝态氮和天门冬素为最佳氮源, 在有无光照条件下均能良好生长。短光波全光照促进产孢, 自然散射光抑制产孢, 苹果组织液明显促进孢子萌发。
From 1996 to 1998, four isolates of apple spotted leaf spot in Jiaodong area were isolated and cultured for pathogenicity. Two different strains A1 and A2 of Alternaria alternata f. Sp. M ali were obtained. On the PDA medium, the A1 colony was dark green on the front surface, with very few aerial hyphae and large amount of sporulation. The conidia size was 17.1-49.0 μm × 7.3-14.7 μm. The positive A2 colony was gray-white and the aerial mycelium was strong. Sporulation less, generally only about 1/5 of the former, the conidia size of 29.4 ~ 63.7 μm × 12.5 ~ 22.1 μm, sporador, beak long spores are more common. A2 was significantly more pathogenic than A1. Large irregular field caused by A2 large. The optimal temperature for growth and development of the two strains were 30 ℃ and 28 ℃ respectively, the optimum pH was 7, glucose and sucrose were the best carbon sources, nitrate nitrogen and asparagine were the best nitrogen sources, Under light conditions can grow well. Short light wave to promote sporulation full light, natural light scattering inhibit spores, apple tissue fluid significantly promote spore germination.