以黑龙江省3个地区洋葱紫斑病植株为试材,采用组织分离法分离洋葱紫斑病病原菌,对获得菌株进行致病性测定、形态学鉴定以及16srDNA ITS序列分析,并研究其生物学特性。结果表明:该致病菌为葱链格孢菌(Alternaria porri(Ell.)Cifferri),该菌株在以葡萄糖为碳源时产孢量最高,但菌丝生长量最低;在以氯化铵为氮源时菌丝生长量和产孢量都达到最高。32℃,pH 7,光照条件为12h光照/12h黑暗交替培养菌丝生长量最高;24℃,pH 8,连续黑暗条件下产孢量最高。 Pathogenicity, morphological identification and ITS sequence analysis of 16srDNA ITS isolates were isolated by tissue isolation method and their biological characteristics were studied using onion purple spot disease in three areas of Heilongjiang Province as tested materials. The results showed that the pathogen was Alternaria porri (Ell.) Cifferri, which had the highest sporulation rate but the lowest mycelium growth rate with glucose as carbon source. The amount of mycelial growth and sporulation reached the highest when nitrogen source was applied. 32 ℃, pH 7, light conditions 12h light / 12h dark alternate culture mycelium growth highest; 24 ℃, pH 8, the highest sporulation under continuous dark conditions.