Agriculture and Farming Atlas
Rice Blast: The Laboratory Fungus Now Jumping To Wheat
Most pages about rice blast frame it purely as a crop threat, and by that measure it already earns the label. Caused by the fungus Magnaporthe oryzae, rice blast is considered the single most destructive disease of cultivated rice worldwide, and it destroys enough rice in an ordinary year to feed tens of millions of people. But agriculture is not the whole story: the same fungus is also studied as a model organism, valued in the laboratory for reasons that go beyond the crop it damages.
That laboratory interest turns out to matter well beyond the lab. Genetic study has found that Magnaporthe oryzae is not one thing but a cryptic species complex, made up of at least two biological species that look alike but carry clear genetic differences and do not interbreed. One of those host adapted lineages has since jumped from rice to wheat: wheat blast, caused by the same fungus in a wheat adapted form, is now an emerging disease of growing concern in South America and South Asia. A question that started as taxonomy, how many species are hiding inside one name, turns out to describe the very mechanism by which a rice disease became a wheat disease too.
Where To Read More
- Rice BlastFungal Diseases of CropsSubject of the essay.
- RiceCereals and PseudocerealsRice, the crop rice blast damages: the destructive-disease framing this essay opens with, before turning to the laboratory angle.
- Magnaporthe oryzaeFungal Diseases of CropsThe fungal species discussed by name.