Characterization of Two Strains of Cowpea Mild Mottle Virus Naturally Infecting Groundnut (Arachis hypogaea L.) in India

Two viruses were isolated from commercial groundnut plants showing mild mottle (MM) and severe mottle (SM) symptoms in the Rayalaseema area of Andhra Pradesh State, India. The host range of both the isolates was restricted to Fabaceae. The physical properties of both isolates were: DEP 10^-6 to 10^-7. TIP 70–85 C and LIV 5–8 days. Partially purified virus preparations contained slightly flexuous filamentous particles. In ELISA and gel diffusion tests both isolates reacted similarly with anusera to the carlaviruses cowpea mild mottle, cassia mild mosaic and potato M. Particle morphology. sedimentation coefficient, and estimated sizes of the coat proteins and RNAs gave additional evidence that the viruses were carlaviruses. Bemisia labaci transmitted only the MM isolate and the two isolates also differed in electrophoretic mobility of intact particles and amino acid composition of the coat proteins. The isolates are identified as distinct strains of cowpea mild mottle virus.