“It is invisible to the naked eye, and can travel hundred kilometres a day destroying nearly everything in its path” … the deadly mutant making news headlines has nothing to see with the merciless Predator, its nickname is UG99 (TTKSK), alias Puccinia graminis f. sp. tritici, a basidiomycetous fungal pathogen from the Pucciniales clade. Two new forms of Ug99 able to overcome the effects of wheat resistance genes have been detected in South Africa. The discovery of these new variants marks the first time that the stem rust fungus with virulence against crucial defense resistance mechanisms (it overcome the effects of the resistance genes Sr31 and Sr24) has moved south of its origins in Uganda in East Africa. Epidemiologists now worry that next stop of the deadly journey of this wind-borne cereal-killer may be the wheat fields, the breadbaskets of the Middle East and South Asia.
To know more about the stem rust threathening world food supply :
Photo: Another rust, the poplar foliar rust (© B Pêtre – INRA).