Maize Lethal Necrosis Disease

Maize lethal necrosis (MLN disease, MLND, corn-lethal necrosis) is a disease affecting corn (maize) mainly in eastern Africa. It is triggered by two viral infections, one from the MCMoV (corn chlorotic mottle virus) and the Potyviridae group: MDMV (corn atrophic mosaic virus), WSMV (wheat streak mosaic virus), SCMV (sugarcane mosaic virus) waiting . [1]

According to the report, at the end of 2014, MLND was able to reduce Kenya's corn production by 30%. [2] Early in March 2015, the loss was estimated at 10% in the middle of the rainy season. [3]

Maize lethal necrosis (MLND) is a combination of two viruses, one of corn chlorotic mottle virus (MCMoV) and a group of Potyviridae such as sugar cane mosaic virus (SCMV), wheat streak mosaic virus (WSMV) Results. ) Or corn atrophy mosaic virus (MDMV). Dual infection of these two viruses results in so-called MLND, also known as corn-killed necrosis (CLN).

The symptoms of lethal necrosis of corn (Photo 1a and Photo 1b) are synergistic co-infections of the symptoms of corn and corn's chlorotic mottle virus (Photo 2) and viruses of Potyviridae family such as wheat streak mosaic virus, short corn It is caused by. Symptoms of mosaic virus or symptoms of sugar cane mosaic virus (original corn atrophic mosaic virus - B) (picture 3). The infection of each virus alone causes more mild symptoms, but when the combined infection of the corn mottled mosaic virus and any potato virus produces a synergistic response it causes plant death. In many cases it is known that symptoms of fatal necrosis in maize appear only with corn chlorotic mottle virus infection under abiotic stress conditions such as drought and low nitrogen.

A serious epidemic in Kenya was later diagnosed as fatal necrosis of corn and was first reported in Longisa branch in Bomet district in September 2011. By 2012, symptoms consistent with fatal necrosis of corn were observed in parts of Central Kenya, Ni Ansa, West and Rift Valley. Since then, Rwanda and the Democratic Republic of the Congo have reported this disease. Similar corn symptoms have been reported in Uganda and Tanzania and more recently in South Sudan and Ethiopia. Recent discussions with pathologists in Tanzania have cast doubt that the disease may have occurred in Tanzania's Mtwara, Tanzania, bordering northern Mozambique