Out of Uganda: An Aggressive Crop Killer That Threatens Global Food

Friday, April 6th, 2018

Mary Williams, Plantae

Food security is a concern of growing importance as the population grows. Not only is crop production importance, but of equal importance is crop health which directly impacts crop production. Scientist at Plantae have found a plant disease called wheat rust which is decimating farmer wheat supplies. Learn more about this fungal plant disease and what scientist are doing to stop it. 

There was a time when one of the most dangerous crop diseases a wheat farmer could encounter in the field was stem rust. It is caused by a fungus, and its spores look like flecks of rust on metal — first red, later black in color. The fungus spreads along stems and leaves of cereal plants, consuming nutrients and causing the grains to shrivel.

Crops affected by stem rust are often entirely destroyed, and until the 1950s, the fungus was able to wreak havoc on agriculture across the globe — including in the United States. Researchers eventually managed to identify strong resistance genes against the fungus, and successfully bred those genes into new plant varieties beginning in the 1960s, leaving the fungus all but forgotten.

A generation later, however a new strain of wheat stem rust appeared — this time in Uganda in 1998. This new strain, which scientists called Ug99 (Ug for the country where it was first discovered, 99 for the year when it was officially named), was immune to most of the known resistance genes — and it remains a threat today. It is more aggressive than most known stem rusts, and it evolves far more quickly. Indeed, where there was only one strain in 1999, there are now at least 13 new pathotypes of Ug99, and they are spreading fast.

Read more at Plantae.