摘要： 为明确京郊快菜软腐病的病原，对取自北京不同区县的发病快菜植株进行组织病原菌分离、培养和回接试验，在形态学观察的基础上，对病原菌株进行了生理生化测定、分子生物学鉴定和致病力分析。结果表明，在分离纯化得到的29株菌株中，17株被鉴定为胡萝卜软腐果胶杆菌巴西亚种，其余12株被鉴定为胡萝卜软腐果胶杆菌胡萝卜亚种；同时也识别到9株非典型Pcc菌株，表现为不能分解柠檬酸盐或不具备在37℃和7% NaCl条件下生长的能力，可微弱利用D-阿拉伯糖醇、异麦芽酮糖醇和D-麦芽糖。致病力测试结果显示，仅2株Pcb菌株和1株Pcc菌株表现为中等致病力，其余菌株均表现为高等致病力。明确了引发北京地区快菜软腐病致病菌的种类为Pcb和Pcc，且致病力普遍较强，可为其防控提供理论依据。

关键词: 快菜, 细菌性软腐病, 病原鉴定, 胡萝卜软腐果胶杆菌

Abstract: To identify the pathogens causing bacterial soft rot on Chinese cabbage in Beijng,29 pathogenic strains were isolated and cultured from diseased samples,which were collected from several districts in Beijing. Morphology analyses,physiological and biochemical tests,molecular assay and pathogenicity test were performed to elucidate the causative bacterial pathogens. The results showed that the 17 strains were identified as Pectobacterium carotovorum subsp.brasiliensis (Pcb),and the remaining 12 strains were identified as P. carotovorum subsp. carotovorum (Pcc). Moreover,there were 9 atypical Pcc strains,which were unable to degrade citrate,or failed to grow at 37℃ and 7% NaCl,or weakly utilized palatinose,D-maltose and D-arabitol. The results of the pathogenicity analysis showed that all the strains expressed high pathogenicity with the exception of 2 Pcb strains and 1 Pcc strain exhibiting medium pathogenicity. The bacterial soft rot disease of Brassica rapa subsp. pekinensis occurred in Beijing and was caused mainly by Pcb and Pcc with high virulence,which will provide the basis for the disease control.

Key words: Chinese cabbage, Bacterial soft rot, Pathogen identification, Pectobacterium carotovorum

中图分类号: 

• S432.1