MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF SCLEROTIUM ROLFSII ASSOCIATED WITH LEAF BLIGHT DISEASE OF PSYCHOTRIA NERVOSA (WILD COFFEE)

Psychotria nervosa (Rubiaceae), commonly known as wild coffee, was found affected by leaf blight disease in the forest regions of Mysore, Madikeri and Hassan districts of Karnataka state (India). Characteristic leaf blight symptoms were observed at the centre of leaf lamina of basal leaves and tiny sclerotial bodies entangled in mycelia were prominent on the adaxial leaf surface. The associated fungal pathogen was isolated and identified as Sclerotium rolfsii on the basis of morphological characters and sequence analysis of ITS region of rDNA. The sequences shared 100% similarity with reliable sequence of S. rolfsii retrieved from GenBank. The detached leaf assay produced leaf blight symptoms seven days after inoculation. S. rolfsii known to infects a wide range of host plants including forest tree species. This is the first report of S. rolfsii causing leaf blight disease of wild coffee in India.