Researchers Learn from Plant Viruses to Protect Crops

By Claire Asher. Reblogged from The Scientist magazine.

MICROSCOPIC WAR: The leaves of this corn plant redden as a result of infection by maize chlorotic dwarf virus, which caused severe crop losses in the midwest and southern United States in the 1960s and ’70s.© BILL BARKSDALE/DESIGN PICS/GETTY IMAGES

In 2011, Noah Phiri was working with local farmers in Kenya to combat the fungal pathogen that causes coffee leaf rust when another virulent plant disease began wiping out maize in the country’s southwest corner. Infected plants developed pale streaks on their leaves, then wilted and died. Some farmers lost as much as 90 percent of their crop that year. Phiri, a plant pathologist at the U.K.-based Centre for Agriculture and Biosciences International (CABI), raced to identify the culprit. He and his colleagues collected samples of sick plants and sent them off to the plant clinic at the Food and Environment Research Agency (now Fera Science) in York, U.K. There, researchers sequenced RNA molecules expressed in the infected corn and identified two viruses that were at the root of the epidemic.

Continue reading in the February 2018 issue of The Scientist→

La Necrosis letal del maíz amenaza la producción en América del Sur

English version below the break.
Artículo elaborado por Joao A. Jeque Junior, Léna Durocher-Granger y José Gómez Vargas.

La enfermedad conocida como la necrosis letal del maíz (MLN, por sus siglas en inglés), causada por la co-infección de dos virus, está amenazando la producción de maíz en el Ecuador. Según el Ministerio de Agricultura, la incidencia y severidad de la enfermedad fue de casi 14% en 2016 y estaba presente en las provincias de Guayas, Los Ríos, Manabí y Loja. Aunque no está claro cómo y cuándo la enfermedad entró en el país, se están haciendo esfuerzos por las organizaciones nacionales de protección fitosanitaria para controlar la propagación de la enfermedad, así como para cuantificar los daños.

Maize lethal necrosis disease symptoms. Naivasha, Kenya. March 2
Síntomas de la Necrosis letal del maíz/Maize lethal necrosis disease symptoms. Naivasha, Kenya. March 2012 (©CABI/Rob Reeder-2012)

Esta enfermedad es causada por la co-infección del virus del moteado clorótico del maíz (MCMV) y del virus  mosaico de la caña de azúcar (SCMV). En África, se detectó la enfermedad por primera vez en 2011 en el distrito de Bomet, Kenia. En 2012 un estudio realizado en los distritos de Bormet y Naivasha, Kenia, mediante la secuenciación de alto rendimiento de muestras de hojas de maíz recogidas en la clínica de plantas Plantwise, ayudó a confirmar la presencia del virus MCMV y SCMV en el maíz (Adams et al., 2012). Debido a  que la enfermedad puede propagarse rápidamente (en menos de una semana), en  4 años se han reportado casos de la sintomatología de la enfermedad en Tanzania, Ruanda, Uganda, Sudán del Sur y la República Democrática del Congo (RDC), y su presencia se confirmó en Tanzania y RDC en 2012 (Makumbi & Wangai, sin fecha).

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Update: Plant Health News (10 Apr 15)

Onions in storage in Burkina Faso © André de Jager, IFDC
Onions can be affected by pests in storage, reducing the value of the crop © André de Jager, IFDC

Here’s a taste of some of the latest stories about plant health, including the identification of genes that increase resistance to potato late blight, improved onion storage in Burkina Faso and the identification of a natural bacterium that kills plantain moth larvae.

Click on the link to read more of the latest plant health news!
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Maize Lethal Necrosis Disease Spreads To Uganda

Maize plants showing Maize Lethal Necrosis disease © CIMMYT via Flickr (License CC-BY-NC-SA 2.0)
Maize plants showing Maize Lethal Necrosis disease © CIMMYT via Flickr (License CC-BY-NC-SA 2.0)

Maize Lethal Necrosis disease, which was first reported in Kenya and Tanzania, has now spread to Uganda, raising concerns for food security in the country. The Ministry of Agriculture has warned that Maize Lethal Necrosis has been reported in districts in eastern Uganda, including Busia and Tororo.

A spokesman for the Agriculture Research Organisation, Robert Anguzo, has said that Ugandan scientists are working in collaboration with the International Maize and Wheat Improvement Centre (CIMMYT) to find management solutions to the disease.

More information about the pests and viruses associated with Maize Lethal Necrosis and the management of the disease can be found on the Plantwise Knowledge Bank

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