中文摘要：

【目的】明确在中国发生的梨花枯和芽枯的确切病原菌。【方法】用普通细菌学方法、电镜观察、Koch氏病原假说测定、Biolog、脂肪酸分析、PCR及与标准对照菌株的比较。【结果】从16个病样中分离获得12菌株,6株代表菌株显示出与Pseudomonas syringaepv.syringae3株标准对照菌株相似的致病反应,它们的Biolog和脂肪酸分析的相似度分别为0.57～0.86和0.58～0.81,PCR和序列测定结合上述结果证实了P.syringaepv.syringae为该病的病原菌。【结论】首次证实了中国梨树上的花枯和芽枯可由P.syringaepv.syringae引起。

英文摘要：

[Objective] This study was made to determine the causal organism of pear blossom and bud blast in China. [Method] The causal organism was identified by bacteriological test, electro- microscopic observation, Koch＇s postulation test, Biolog, fatty acid methyl esters （FAMEs） and PCR test and compared with the standard strains. [Result]Six representative strains out of 20 pathogenic bacterial isolates from 16 diseased samples showed characteristics similar to 3 standard strains of Pseudomonas syringae pv. syringae from Belgium. They were identified as P. syringae pv. syringae with Biolog similarity of 0.57-0.86 and FAMEs similarity of 0.58-0.81. The bacterium was reisolated from symptomatic plants and blossoms. Identification as P. syringae pv. syringae was confirmed by using PCR primers and sequences test and combined with the above results. [Conclusion] It has been confirmed that the pear blossom and bud blast in China may caused by P. syringae pv. syringae.