Occurrence of a new necrosis viral disease of blackgram (Vigna mungo) and identification using electron microscopy and ELISA technique

Abstract

A new necrosis viral disease was observed in blackgram, showed brown necrotic rings along with veinal and stem necrosis. The virus was mechanically inoculated on the local lesion host, cowpea cv. 152 and maintained in the local lesion host throughout the study. Yield studies under pot culture experiment showed 10- to 30-day-old plants were highly susceptible and the yield became almost nil. By using Transmission Electron Microscope (TEM) and indirect Direct Antigen Coated-Enzyme Linked Immuno-Sorbent Assay (DAC-ELISA) studies the virus was identified as Tobacco streak virus (TSV). The ultraviolet absorbance of the purified virus was measured and the ratio of A260/A280 was determined as 1.41. Polyclonal antiserum was raised against blackgram necrosis virus in New Zealand white rabbit and the titre value was determined as 1: 200. Direct antigen coating-ELISA was used to detect the virus concentration in various plant parts and stem portion recorded maximum virus concentration. TSV in blackgram was not transmitted through seeds.