Insights of maize lethal necrotic disease: A major constraint to maize production in East Africa

Abstract

Maize Lethal Necrotic Disease (MLND) is a new disease in East Africa, first reported in Kenya in 2011 and then spread to Tanzania, Uganda and Rwanda. The disease is caused by Maize Chlorotic Mottle Virus (MCMV) in combination with viruses of genus Potyvirus, mostly Sugarcane Chlorotic Mottle Virus (SCMV). The co-infection is the one that results in intensive to complete yield loss. Diagnosis of MLND based on symptoms is reported ineffective because symptoms like stunting and chlorosis resembles nutrient deficiencies or maize mosaic. Detection and characterization of MLND causing viruses have been done by techniques such as enzyme-linked immuno-sorbent assay (ELISA), polymerase chain reaction (PCR) and next generation sequencing. Relatively little work has been done to characterize MLND causing viruses in Tanzania prior to those techniques. The disease can be managed through the use of certified seeds, sanitation, quarantine, crop rotation, the use of resistant/tolerant maize varieties and other cultural practices. The use of resistant maize varieties is considered the most reliable, eco-friendly, effective and economical way of managing MLND. Key words: Enzyme-linked immuno-sorbent assay (ELISA), etiology, Maize Chlorotic Mottle Virus, Maize lethal necrotic disease, nucleic acid based methods, resistant maize varieties, Sugarcane Chlorotic Mottle Virus.