Investigation of Multiple Pathogens in Black-Spotted Dendrobium officinale Based on Culture-Independent and Dependent Methods

摘要

Black spot disease which significantly reduces the quality of medicine plants is quite common in Dendrobium officinale fields. In this study, GXDF33, a strain of Alternaria, together with the reported pathogen Cladosporium, was isolated from symptomatic leaves. The in vitro pathogenicity tests on seedlings showed GXDF33 can cause black spot disease. Based on quantitative real-time polymerase chain reaction (qPCR) result, it was found that the biomass of both Cladosporium and Alternaria increased as the symptom went severer. According to amplicon sequencing data for the symptomatic samples from Guangxi and Zhejiang Provinces in China, Cladosporium and Alternaria were both common genera in symptomatic plants. To our knowledge, this is the first report unveiling the relationship between black spot disease of a officirrale and Ciadosportum as well as Alternaria.