Biological, Serological and Molecular Characterisation of a New Virus Species Infecting Telfairia occidentalis in Calabar, Cross River State, Nigeria
O. I. Eyong
Department of Forestry and Wildlife Management, Cross River State University of Technology, Nigeria.
A. T. Owolabi
Department of Botany, University of Calabar, Calabar, Nigeria.
A. A. J. Mofunanya *
Department of Botany, University of Calabar, Calabar, Nigeria.
E. E. Ekpiken
Department of Plant Science and Ecological Studies, Cross River State University of Technology, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Telfairia occidentalis (Hook) belongs to the family Cucurbitaceae and is an economically important cash crop worldwide. It is widely cultivated in Nigeria including the South Eastern part of the country. This research was aimed at isolating, characterising and identifying a new virus species infecting Telfairia occidentalis in Calabar, Cross River State. Diagnostic tools employed included host range/symptomatology, insect transmission test, Antigen Coated Plate (ACP) Enzyme Linked-Immunosorbent Assay (ELISA) and gene sequencing. Results revealed that the virus isolate infected only members of the cucurbit family producing rugosity, mosaic, mottle and leaf malformation/deformation. The virus isolate was transmitted by Aphis spiraecola in a fore-gut manner and not by A. citricida. It reacted positively against universal potyvirus antiserum. Sequence analysis showed that the Telfairia occidentalis virus isolate had 75% sequence identity with Moroccan watermelon mosaic virus (MWM) which was found to be the closest. The virus was consequently considered a new species of potyvirus for which the name Telfairia severe mosaic virus (TeSMV) was suggested.
Keywords: Telfairia occidentalis, ACP-ELISA, Potyvirus, Telfairia severe mosaic virus.