Soft-rot disease on Dendrobium nobile observed in a commercial farm in the Nilgiris district of Tamil Nadu, India was investigated. Disease etiology is reported along with phenotypic, molecular identification of the pathogen. Infected leaves showed rot symptoms characterized by irregular water-soaked lesions on the leaf margin that rapidly spread over the entire leaf. Milky exudation on the cut end of infected leaves indicated the bacterial etiology of the disease. The bacterial colonies isolated were irregular, whitish-yellow, spindle-shaped with a characteristic raised center. All isolates showed identical phenotypic traits and induced a hypersensitive reaction on Nicotiana tabacum leaves. Pathogenicity assay performed on D. nobile confirmed their pathogenic nature as all three bacterial isolates incited typical soft-rot within 12 h post-inoculation (hpi). In vitro host range studies revealed that all the isolates could cause rot on cut slices of other vegetable crops including potato, carrot, and onion. Additionally, the bacterium incited soft rot on Aloe vera, but not on chrysanthemum and banana transplants. The identity of the bacterial isolates was confirmed as Dickeya fangzhongdai using 16S rRNA gene sequences as well as by their pathogenic behavior. Complete understanding of the etiology of the disease and of the pathogen would be useful to devise suitable management practices for the containment of disease spread in the future.

在印度泰米尔纳德邦的尼尔吉里斯（Nilgiris）地区的一个商业农场中，观察到了高铁皮石D上的软腐病。病因与表型，病原体的分子鉴定一起被报道。被感染的叶片表现出腐烂症状，其特征是叶片边缘不规则的浸水病灶迅速扩散到整个叶片上。感染叶片切端的乳白色渗出表明该病的细菌病因。分离出的细菌菌落是不规则的，发白的黄色，纺锤形，具有特征性的凸起中心。所有分离株均表现出相同的表型性状，并在烟草叶片上引起过敏反应。对诺维石。进行致病性测定证实了它们的致病性，因为所有三种细菌分离物在接种后（hpi）12小时内均引发了典型的软腐病。体外寄主范围研究表明，所有分离株都可能在其他蔬菜作物（包括马铃薯，胡萝卜和洋葱）的切成薄片上引起腐烂。另外，该细菌在芦荟上引起软腐，但在菊花和香蕉移植上不引起软腐。使用16S rRNA基因序列及其致病行为，确认了细菌分离株的身份为Dickeya fangzhongdai。全面了解疾病和病原体的病因将有助于设计适当的管理方法，以遏制将来传播的疾病。