Isolation and identification of pathogens causing dragon stripe disease on Kadsura coccinea

The Kadsura coccinea (commonly known as black tiger plant) is an edible plant with wide applications in traditional Chinese medicine and is an important source for various bioactive metabolites. The incidence of dragon stripe disease, a serious infection caused by various fungal pathogens, is high in K. coccinea. The disease result in reduced productivity of the plant and thereby cause economic loss to the farmers. It is therefore necessary to have clear information on the pathogenic strains of fungi that causes dragon stripe disease on K. coccinea for its effective diagnosis and management. The study isolated and purified different pathogenic microorganisms, which were further, identified using sequence analysis and phylogenetic tree construction of rDNA-ITS genes. The pathogenicity of the identified organisms was verified according to Koch's rule. A total of 26 fungi were isolated from 100 pieces of fungal infected leaf tissues. The major ones were Apiospora jiangxiensis, Apiospora chromolaenae, Neopestalotiopsis formicarum, Diaporthe kochmanii, Diaporthe longicolla, Botryosphaeria fabicerciana, and Alternaria alstroemeriae. The present study first report that the K. coccinea as a host for Neopestalotiopsis formicarum. Another six species of fungi identified may exist in the plant tissues of K. coccinea as endophytic or saprophytic fungi, the role of which need to be further evaluated. Overall, the results of the study may be useful for the understanding of the pathogenic nature of dragon stripe disease on K. coccinea, as well as to provide a basis for field diagnosis and comprehensive management of the disease.