Identification and determination of some properties of Peanut Mottle Virus using biological and serological methods in Guilan Province.
Peanut mottle virus (PeMoV) is one of the major viral pathogens of peanut [groundnut], soyabean (Glycine max) and some other legumes in the world. Peanut leaf samples with symptoms of mottling and mosaic were collected from different growing fields in Guilan province, Iran. The virus was identified using biological and serological tests of ELISA with PeMoV-specific antibody and antibody of a commercial Kit. In mechanical inoculation, leaf extract of ELISA-positive samples was prepared in 0.1 M phosphate buffer with pH 7 containing 1.5 ml sodium diethyldithiocarbamate and inoculated to a series of host plants in a greenhouse. Soyabean and peanut plants reacted with mottling and mosaic or mild mosaic symptoms. French bean (Phaseolus vulgaris cv. Top Crop) reacted with necrotic local lesions extending to the veins. A local cultivar of cowpea reacted with systemic symptom. Chenopodium amaranticolor, C. quinoa, Vicia faba (cv. Barakat), French bean (cv. Bountiful), Nicotiana tabacum (cultivars Rustica and cocker) were not infected by the virus inoculation. The level of seedborne infection of the virus was 2 and 3% in peanut and soyabean seeds, respectively. Myzus persicae and Aphis gossypii transmitted PeMoV from infected plants to healthy soyabean and peanut plants in a non persistence manner. The virus was propagated in soyabean host and was purified partially. Electron microscopy studies from crude plant extract of soyabean and peanut-virus infected plants revealed elongated flexuous rod shaped virus particles measuring approximately 750 nm long. In TEM decoration tests, the PeMoV-specific antibody completely decorated the virus particles. On the basis of serological and biological properties, the virus was identified as PeMoV. This is the first report of PeMoV occurring in peanut in Guilan province.