This interview was originally published in the journal International Innovation, published by .
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Dr. Lesley Boyd is the 2011 Jeanie Borlaug Laube Women in Triticum Mentor Award winner.
Stripe and stem rust have been around for some time; what is the history of the current epidemic?
Nature has shown us that we must not become complacent with regard to crop disease. The new stem rust race Ug99 made a sudden appearance in Uganda in 1999, and wiped out 70 per cent of the developing world’s wheat varieties. A new, more aggressive race of stripe rust appeared in the U.S. in 2000. This subsequent return of stripe rust epidemics across the U.S. reminds us of the words of the late Nobel Prize winner, Norman Borlaug that "rusts never sleep."
What is the focus of the work being conducted by your research group?
I have led a research programme at the John Innes Centre on wheat-rust interactions since 1995. The focus of the work has been the genetic, biological and molecular characterisation of sources of rust resistance that confer durable resistance. The control of rust in wheat has relied heavily on major, race-specific R-genes. Whilst easy to control in a traditional wheat-breeding programme, their value in a sustainable agricultural system is minimal, any newly introduced R-gene having an effective life on average of 2-4 years. Durable sources of rust resistance are known, but these often confer a partial, developmentally-regulated phenotype, being referred to as Adult Plant Resistance (APR). Our research group’s programme uses DNA markers to genetically define APR for wheat rust, microscopy to determine the biology of different APR genes, and functional genomics to determine the mechanism by which individual APR genes confer resistance.
Can you tell us more specifically about the ‘Sustainable Agriculture Research for International Development’ SARID project?
This is a collaborative project with Professor Zakkie Pretorius, University of the Free State, South Africa, Dr Reneé Prins, CenGen Pty Ltd, and Susanne Dreisigacker of the International Wheat and Maize Development Center, Mexico. I have collaborated with Pretorius and Prins since 1996, when stripe rust first appeared as a field disease of wheat in South Africa. At that point in time no characterisation of stripe rust resistance in South African wheat varieties had ever been undertaken. The threat of the new stem rust Ug99 races originating in Uganda(and prevalent in Kenya and Ethiopia) spreading to the rest of Africa (including South Africa)necessitated the detection of new sources of effective and potentially durable resistance to stripe and stem rust.
What are the project's aims?
The aim of the SARID project has been to identify and develop molecular markers for new sources of APR for both stripe and stem rust that are effective in Africa (and Europe in the case of stripe rust). To do this we have worked to identify non-R-gene type APR genes, and APR genes that confer resistance through different and complementary mechanisms. By combining APR genes conferring complementary mechanisms of resistance we hope to produce new wheat varieties with improved resistance that has the potential to remain effective for longer. International collaboration and capacity building are obviously important SARID objectives, for instance the training o fAfrican students in wheat-rust pathology and cereal marker technologies.
Why do you think this is so integral?
Capacity building is a major focus of this project. We need DNA tools to identify and biologically define new sources of durable APR against the diseases devastating wheat so that we can accumulate them into new wheat varieties for use by small and large scale farmers alike. In doing this it is imperative that a new generation of researchers are trained who understand these aims. If a knowledge-technology transfer pipeline from the developed world into Africa is to be sustainable, then a new generation of individuals, with the required knowledge and skills, needs to be trained. The SARID programme is training African nationals in wheat-rust pathology and cereal marker technologies, which in the case of Gloudi Agenbag will result in the award of a PhD. The student is receiving training in field trial management, rust infection procedures and resistance assessment, statistical and genetic (genetic mapping and QTL analysis)analysis, and molecular marker technologies. These well trained individuals will be a major asset to the future development of modern agriculture in Africa.