A revolutionary method using palm-sized gene sequencers is improving the ability of Ethiopia’s researchers, policymakers and farmers to curtail virulent fungal pathogen outbreaks on wheat.
Rapidly identifying the exact pathogen strain, especially new ones, is crucial to swiftly stopping potential rust outbreaks, which have been compared to wildfires in how they destroy crops and spread. Until now, field researchers have had to send samples to specialized laboratories to identify the exact strain, which is costly and can take months, making preventive action impossible.
Known as Mobile and Real-time Plant Disease Diagnostics (MARPLE) and being tested for wheat yellow rust disease in Ethiopia, the new tool can diagnose pathogen strains in a few days. It builds upon initial development work at the John Innes Centre (JIC) in the UK and represents a collaboration between the International Maize and Wheat Improvement Center (CIMMYT), JIC, and the Ethiopian Institute of Agricultural Research (EIAR).
A major threat to global wheat production since the early 2000s, yellow rust – also called stripe rust – results in wheat grain losses estimated at over 5 million tons annually and worth US $1 billion. The causal pathogen, Puccinia striiformis f.sp. tritici, evolves quickly and its spores easily cross continents on wind currents.
“We were the first to identify yellow rust strains accurately in less than three days,” said Dave Hodson, CIMMYT principal scientist. “We can also find out quickly if the strain is a new one. This is critical for stopping epidemics.”
“MARPLE’s piloting in Ethiopia will help us set up a national wheat rust early warning system. This is aligned with national efforts to attain self-sufficiency for wheat,” added Tadessa Daba, director of Agricultural Biotechnological Research at EIAR.
Ethiopia’s farmers produce more than 4.5 million tons of wheat each year but the country imports over 1 million tons of wheat grain annually to satisfy domestic demand. Rapidly emerging and evolving races of wheat stem rust and stripe rust disease – the crop’s deadliest scourges worldwide– have driven large-scale wheat seed replacement by Ethiopia’s farmers in recent years.
Developed by a John Innes Centre team led by Diane Saunders, MARPLE uses a small, nanopore-technology gene sequencer from Oxford Nanopore Technologies that plugs into a laptop and is easy to use in field conditions. This scientific innovation won 2017 and 2018 prizes from the CGIAR Big Data Platform and matching funds were recently obtained from the Delivering Genetic Gain in Wheat (DGGW) project led by Cornell University.
Further success in 2019
The research team behind the MARPLE diagnostic kit won the International Impact category of the Innovator of the Year 2019 Awards, sponsored by the United Kingdom’s Biotechnology and Biological Sciences Research Council (BBSRC).
The team of Saunders (John Innes Centre), Hodson (CIMMYT) and Daba (EIAR) was presented with the award at an event at the London Science Museum in May 2019.
The BBSRC Innovator of the Year awards, now in their 11th year, recognize and support individuals or teams who have taken discoveries in bioscience and translated them to deliver impact. Reflecting the breadth of research that BBSRC supports, they are awarded in four categories of impact: commercial, societal, international and early career. Daba, Hodson and Saunders were among a select group of 12 finalists competing for the 4 prestigious awards.
“I am delighted that this work has been recognized,” Hodson said. “Wheat rusts are a global threat to agriculture and to the livelihoods of farmers in developing countries such as Ethiopia. MARPLE diagnostics puts state-of-the-art, rapid diagnostic results in the hands of those best placed to respond: researchers on the ground, local governments and farmers.”
Credits:
See CIMMYT Annual Report 2018 for full credits.