title: Maize Lethal Necrosis (MLN), an Emerging Threat to Maize-Based Food Security in Sub-Saharan Africa.
abstract: In sub-Saharan Africa, maize is a staple food and key determinant of food security for smallholder farming communities. Pest and disease outbreaks are key constraints to maize productivity. In September 2011, a serious disease outbreak, later diagnosed as maize lethal necrosis (MLN), was reported on maize in Kenya. The disease has since been confirmed in Rwanda and the Democratic Republic of Congo, and similar symptoms have been reported in Tanzania, Uganda, South Sudan, and Ethiopia. In 2012, yield losses of up to 90% resulted in an estimated grain loss of 126,000 metric tons valued at $52 million in Kenya alone. In eastern Africa, MLN was found to result from coinfection of maize with Maize chlorotic mottle virus (MCMV) and Sugarcane mosaic virus (SCMV), although MCMV alone appears to cause significant crop losses. We summarize here the results of collaborative research undertaken to understand the biology and epidemiology of MLN in East Africa and to develop disease management strategies, including identification of MLN-tolerant maize germplasm. We discuss recent progress, identify major issues requiring further research, and discuss the possible next steps for effective management of MLN.
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: George
authors.initials: G
authors.lastname: Mahuku
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Benham E
authors.initials: BE
authors.lastname: Lockhart
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Bramwel
authors.initials: B
authors.lastname: Wanjala
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Jones
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Janet Njeri
authors.initials: JN
authors.lastname: Kimunye
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Lucy R
authors.initials: LR
authors.lastname: Stewart
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Cassone
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Subramanian
authors.initials: S
authors.lastname: Sevgan
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Johnson O
authors.initials: JO
authors.lastname: Nyasani
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Kusia
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: P Lava
authors.initials: PL
authors.lastname: Kumar
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: C L
authors.initials: CL
authors.lastname: Niblett
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Andrew
authors.initials: A
authors.lastname: Kiggundu
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Godfrey
authors.initials: G
authors.lastname: Asea
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Hanu R
authors.initials: HR
authors.lastname: Pappu
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Anne
authors.initials: A
authors.lastname: Wangai
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Boddupalli M
authors.initials: BM
authors.lastname: Prasanna
authors.affiliation: First, fifth, and seventeenth authors: International Maize and Wheat Improvement Center (CIMMYT), ICRAF Campus, UN Avenue, Gigiri, PO Box 1041-00621, Nairobi, Kenya; second author: Department of Plant Pathology, University of Minnesota, St. Paul; third and sixteenth authors: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; fourth, sixth, seventh, and eighteenth authors: United States Department of Agriculture-Agricultural Research Service Corn, Soybean and Wheat Quality Research and Department of Plant Pathology, Ohio State University, Wooster 44691; eighth, ninth, and tenth authors: Plant Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya; eleventh author: International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria; twelfth author: Venganza, Inc., 9505 Ocean Shore Blvd., St. Augustine, FL 32080; thirteenth and fourteenth authors: National Agricultural Research Organization, Entebbe, Uganda; and fifteenth author: Department of Plant Pathology, Washington State University, Pullman 99164.
authors.forename: Margaret G
authors.initials: MG
authors.lastname: Redinbaugh
mesh_terms: D017954:Africa South of the Sahara; D005523:Food Supply; D054884:Host-Pathogen Interactions; D010571:Pest Control; D010935:Plant Diseases / Q000821:virology; D019176:Potyviridae / Q000502:physiology*; D019183:Tombusviridae / Q000502:physiology*; D003313:Zea mays / Q000821:virology*