Molecular identification of viruses infecting maize (Zea mays L.) in Ekiti State, south-western Nigeria

Abstract

Maize is one of the most commonly cultivated crops in southwestern Nigeria, but its production is constrained by virus diseases. Information on viruses infecting maize within the region is still limited. Therefore, a survey was conducted to identify the viruses infecting maize on randomly selected farmers' cultivated maize fields in 16 local government areas in Ekiti State, southwestern Nigeria using molecular detection tools. Four cultivated maize fields were randomly surveyed in each local government area with an average size of 50 m x 50 m. The sampling was done on fifty randomly selected plants per field. Viral diseases were confirmed on maize plants through visual symptoms observations and serological diagnosis, although severity and incidence varied per location. Visible symptoms observed include chlorotic patches, severe streaking, red pigments and venation along mid rib and vein with stunted growth. Although only Maize streak virus (MSV) and Maize chlorotic mottle virus (MCMV) were targeted, serological assay indicated the occurrence of only MSV. Polymerase chain reaction (PCR) confirmed the presence of MSV while MCMV was negative. This provides additional information to the prevalence of MSV as an ongoing threat to maize production in southwest Nigeria.

Keywords: Maize streak virus, Maize chlorotic mottle virus, ELISA, Polymerase chain reaction, Symptoms