Detection of cucumber mosaic virus in bell pepper crop from himachal Pradesh

Natural infection of cucumber mosaic virus (CMV) causing mosaic, leaf deformation, ring spots on leaves and fruits of bell pepper plants was detected by biological, serological and molecular assay. The causal virus was found to be mechanical as well as aphid transmitted. The identity of the isolate was established based on symptom expression on indicator plant species, biophysical properties, host range, serology, morphological properties of the virus particles by transmission electron microscopy, and RT-PCR. In ELISA, the virus isolate gave positive reaction with cucumber mosaic virus (CMV) specific antibodies. Myzus persicae Sulz., Aphis craccivora Koch. and Aphis gossypii were serologically tested for presence of CMV. Leaf dip preparations from virus-infected plants in electron microscopy revealed the presence of ~28 nm isometric particles. Virions showed good clumping with antiserum to CMV. 17 weed species were tested as an alternate host of CMV. Bidens pilosa was found to be a new reservoir host for CMV virus. Reverse transcription (RT)-PCR assays with CMV coat protein gene specific primers and total nucleic acid extracted from symptomatic bell pepper leaves yielded the expected ~550bp amplicon.