番茄细菌性髓部坏死病病原细菌的鉴定

Identification of a Pathogen of Bacterial Pith Necrosis in Tomatoes

【目的】对2017–2019年在福建、浙江等地大棚种植的番茄上发现的一种引起番茄细菌性髓部坏死病的新病害进行病原鉴定,为该病害的防治奠定基础。【方法】采用Biolog法、16S rDNA基因序列测定及MALDI-TOFMS等方法对分离的病原菌进行种属鉴定;利用柯赫氏法则进行病原菌的致病性测定。【结果】从田间番茄细菌性髓部坏死病发病植株上分离保存了2个代表性细菌菌株,将2个菌株接种至番茄幼苗上,它们均可侵染番茄植株,造成茎杆维管束褐变,茎髓部组织腐烂、空心,并最终导致整株植株萎蔫死亡。该症状与田间自然发病症状相同,并从回接发病植株上重新分离到相同的病原细菌。经Biolog法、16S rDNA基因序列测定及MALDI-TOF-MS等方法确认该病原菌为阿氏肠杆菌(Enterobacter asburiae)。【结论】福建、浙江等地大棚种植的番茄上发现的引起番茄细菌性髓部坏死病的病原菌为阿氏肠杆菌,该发现尚属国内外首次报道。

【Objective】 The pathogen that caused the bacterial pith necrosis on greenhouse tomatoes grown in Fujian and Zhejiang provinces during 2017-2019 was identified. 【Method】 Biolog analysis, 16 S rDNA gene sequencing, and MALDITOF-MS were performed to identify the pathogen. The Koch’s rule was employed to determine the pathogenicity of the isolate.【Result】 Two bacteria strains were isolated from the diseased tomatoes. The symptoms of discolored, dark brown vascular tissue and pith of main stem observed on tomatoes in the laboratory were identical to those found in the field. The bacteria were re-isolated from the infected plants and identified as Enterobacter asburiae. 【Conclusion】 The pathogen that caused bacterial pith necrosis in tomatoes in Fujian and Zhejiang was identified and reported as E. asburiae for the first time.