First report of lethal necrosis disease associated with co-infection of finger millet with Maize chlorotic mottle virus and Sugarcane mosaic virus in Kenya.
In 2011, maize lethal necrosis (MLN) was reported from Bomet, Kenya, as a result of coinfection of maize with Maize chlorotic mottle virus (MCMV) (genus Machlomovirus) and Sugarcane mosaic virus (SCMV) (genus Potyvirus). MLN was later reported from other locations in Kenya and other African countries. During a survey (March to June 2014) for alternate hosts of MCMV and SCMV in MLN hotspots of Bomet and Nyamira, leaves from finger millet with symptoms of viral infection were sampled. Symptoms included chlorotic mottle from the base of young leaf whorls upward to the tips, and necrosis from leaf margins to the midrib. Aphids (Rhopalosiphum sp., Sitobion avenae) and corn thrips (Frankliniella williamsi), which are known vectors of SCMV and MCMV, respectively, were collected from the finger millet and identified. Based on the results of DAS-ELISA test, RT-PCR assay and nucleotide sequence analysis, the presence of the two viruses on finger millet was confirmed. This is thought to be the first report on occurrence of lethal necrosis in finger millet from Kenya or elsewhere.