The gene that has provided spring barley with resistance to powdery mildew for over 30 years increases susceptibility to newly-important disease Ramularia leaf spot.
Scientists confirm the trade-off in a paper published in the Journal of Experimental Botany. Since 1980, the mlo gene has transformed mildew from the most important disease of barley to an occasional nuisance in wetter areas of the UK.
"Having suspected that one of the most successful and widely-used resistances to an important crop disease has the detrimental effect of increasing susceptibility to another, we took a closer look," says Professor James Brown from the John Innes Centre.