Andrographis paniculata (Burn F. Nees) - A new host for root rot pathogen Macrophomina phaseolina Tassi. (Goid)

Andrographis paniculata (Burn F. Nees) is one of the most popular annual, medicinal herb belonging to the Acanthaceae family. It is widely planted in India for its use in the treatment of array of mammalian diseases. Root rot like symptoms were observed on A. paniculata plants grown in University Farm, Coimbatore, India. During field visit, typical symptoms of foliar yellowing, wilting, bark shredding and rotting of roots were observed in A. paniculata. The disease incidence was recorded up to 55%. The fungus associated with root rot was identified as Macrophomina phaseolina based on morphological and molecular studies. Septate colored mycelium with oblong to irregular shaped sclerotia was microscopically documented in culture. Pathogenicity tests confirmed through Koch's postulates revealed similar root rot symptoms. Further, the PCR assays using the genomic DNA of fungus with primer pair of internal transcribed spacer region and nucleotide sequence comparison confirmed the association of M. phaseolina. In our study, we have reported A. paniculata as a new host for the root rot pathogen, M. phaseolina.