Partial characterization and identification of a virus associated with stunt disease of black pepper (Piper nigrum) in South India

A virus associated with stunt disease of black pepper (Piper nigrum) in Sou th India was purified and partially characterized. The virus was transmitte d through stem cuttings of black pepper and by grafting. It was also sap-tr ansmitted with difficulty from black pepper to black pepper and to a few ex perimental plants. Chenopodium amaranticolor, C, quinoa, Vigna unguiculata, V, radiata and V. mungo reacted with local chlorotic/necrotic lesions. Cuc umis sativus and five tested solanaceous plants reacted with systemic mosai c symptoms. The leaf extract of diseased black pepper or virus purified fro m diseased black pepper leaves in direct antigen coating-ELISA and electrob lot immunoassay tests reacted positively with polyclonal antisera of cucumb er mosaic cucumovirus (CMV)-Banana (India), CMV-Brinjal (India), Ch IV-Chil li (India),. CMV-Tomato (India), CMV-L (USA) and CMV-A (China), The negativ ely stained purified virus preparation contained non-enveloped isometric vi rions. The M-r of double-stranded (ds) RNAs isolated from infected black pe pper leaves was 2.42, 2.20 and 1.62 x 10(6) De. The coat protein of disrupt ed purified virions in 12% SDS-PAGE was resolved into one major polypeptide with M-r 26.1 kDa and of nucleic acid in 1% agarose gel resolved into four species with M-r 1.21, 1.10, 0.81 and 0.37 x 10(6) Da, Particle morphology , antigenic relationships with CMV, coat protein and genome characteristics suggest that the virus associated with stunt disease of black pepper in th e state of Kerala, South India could be an isolate of CMV.