Evaluating the incidence and severity of rice yellow mottle virus and maize streak virus on rice (Oryza sativa L.) and associated insects in the Federal Capital Territory, Abuja, Nigeria

Abstract

Rice is an important staple food in Nigeria, affected by several diseases especially viruses. This study was carried out to evaluate the incidence and severity of two important viruses on rice plants and to identify associated insects in the Federal Capital Territory (F.C.T), Abuja in 2019. Field experiment was carried out from June to October, 2019 at the Teaching and Research Farm of the Faculty of Agriculture, University of Abuja, Nigeria, where ten rice varieties were assessed for incidence and severity. The seed and leaf samples were collected for serological indexing. Data collected was subjected to statistical analysis using SPSS and mean separation was done with Duncan Multiple Range Test. Of the 210 leaf samples collected, FARO 61 and 44 had the lowest incidence (19%), while FARO 65 recorded the highest (25.3%). FARO 52 recorded the highest severity (46%) while FARO 61 and FARO 60 had the lowest severity (30.1%) for rice yellow mottle sobemo-virus (RYMV) and maize streak geminivirus (MSV). Insects such as Spittle bug (Locris rubens and Poophilus costalis), Ladybird beetle (Cheilomenes sulphurea) and Groundhopper (Paratettix sp) were trapped on the field. All rice seed and leaf samples collected did not test positive to RYMV and MSV using Enzyme-Linked immunosorbent assay (ELISA). This study provides the first research work on rice viruses in the FCT and further studies are recommended.   Key words: Nigeria, rice, rice yellow mottle sobemo-virus (RYMV), maize streak geminivirus (MSV), incidence, severity, virus symptoms, enzyme linked immuno sorbent assay (ELISA).