First report of Leucobacter aridicollis causes leaf spot disease on Dendrobium officinale in Guizhou Province, China

Dendrobium officinale (Kimura and Migo) is a precious herb cultivated in lots of provinces in China. During a investigation in April 2022, we observed some leaf spot symptoms in the D. officinale field in Guizhou Province, China. Samples of diseased leaves in D. officinale showed spot symptoms (yellow speckle, brown necrotic sunken and emerged lesions). The study obtained two isolates from collected samples, which were characterised by morpho-molecular phylogenetic analysis and pathogenicity tests on D. officinale leaves. The colony belonged to gram-positive bacteria and was rod-shaped. The pathogens were identified as Leucobacter aridicollis. The pathogenicity test declared that L. aridicollis might cause spot similarly symptoms as detected in field, thus confirming that L. aridicollis was the pathogen for leaf spot disease on D. officinale. As is well known, this study is reported for the first time L. aridicollis causing leaf spot disease on D. officinale. The study should provide vital theories into the management of diseases D. officinale in field.