Wheat relatives harbour supply of resistance genes

SciDev.net: Researchers have shown that wild relatives of cultivated wheat exhibit resistance to a number of fungal diseases, and could provide a source of resistance genes to introduce into cultivated wheat. They published their findings in August issue of the journal Plant Disease.

Lead researcher Brian Steffenson, plant pathologist at the US-based University of Minnesota, and colleagues have shown that there is a high level of disease resistance in samples of Sharon goatgrass (Aegilops sharonensis) collected from southern Lebanon and the Israeli Coastal Plain.

For example, they found that around 70 per cent of the goatgrass samples were resistant to a certain type of stem rust, a fungal disease that threatens much of the world's wheat crops (see Deadly wheat disease 'a threat to world food security'). Four out of 107 samples were highly resistant to most of the wheat fungal diseases tested for — powdery mildew, leaf rust, stem rust, stripe rust, tan spot and spot blotch.

Co-author of the paper, Yehoshua Aniksterat, of the Israel-based Institute for Cereal Crops Improvement at Tel Aviv University, told SciDev.Net that although it could be difficult — and take up to five years or more — they may be able to transfer genes from wild to cultivated wheat.

Steffenson told SciDev.Net that wild ancestors of cultivated plants often carry resistance to disease organisms. He said the research project will continue to evaluate wild wheat and barley species for useful genes, not only for disease resistance but also those contributing to higher yield, nutritional quality and adaptation to harsh environments.

Rodomiro Ortiz, director of resource mobilisation at Mexico-based International Maize and Wheat Improvement Center, told SciDev.Net the research reveals the genetic wealth available in wild relatives of important crops such as wheat and is useful for creating new cultivated crops. But more research will be needed to confirm that these wild samples have broad-spectrum resistance and resistance to the most virulent forms of the pathogens, he said.