Two species fused to give rise to plant pest

Jul 12, 2012 by Journal of Plant Pathology and Microbiology

Zymoseptoria tritici is often a headache for European farmers. This ascomycete originating from the Middle East attacks the leaves of wheat plants triggering “speckled leaf blotch”, which can cut crop yields by up to 50 percent. Scientists from the Max Planck Institute for Terrestrial Microbiology in Marburg and Aarhus University in Denmark have now taken a close look at the genome of a close relative, Zymoseptoria pseudotritici and have made a surprising discovery. The fungus which, unlike its more globally active cousin, preferentially attacks grasses in Iran, clearly arose just a few hundred years ago from the fusion of two unknown parent species. The researchers’ results make it clear that entirely new and successful pest species can arise extremely rapidly by natural hybridisation.