Wheat Researcher Says Stem-Rust Disease Is Spreading
This week, the Bill & Melinda Gates Foundation announced a $24 million grant to Cornell University, funding a global wheat research group, known as Delivering Genetic Gain in Wheat. The aim is to develop new lines of wheat that are both heat-tolerant and disease-resistant. David Hodson, senior scientist with the International Maize and Wheat Improvement Center (CIMMYT), based in Addis Ababa, Ethiopia, is part of the research group. He recently sat down with FERN editor-in-chief Sam Fromartz in Washington to discuss the re-emergence of stem-rust disease, a virulent fungal pathogen that attacks wheat plants and causes devastating crop losses, especially in poorer countries. Hodson specializes in pathogen surveillance and runs the website RustTracker.org.
Can you give us the landscape of stem rust now? How far has the disease spread?
We had the initial detection in Uganda in 1998-99, which is where the name Ug99 came from. This original race has now grown to 13, so essentially it’s a very closely related family of stem-rust races. We’ve been able to identify the new races that have occurred, most likely through mutations, and we’ve also been able to track the migration of these races. We’re looking at a distribution now across 13 confirmed countries. From Egypt all the way down to South Africa, every wheat-growing country in eastern and southern Africa has confirmed an Ug99 race.
Is that the wheat-growing region in Africa?
Ethiopia is the biggest producer in sub-Saharan Africa, followed by South Africa. But Egypt is a big producer and also one of the biggest importers of wheat. Wheat is everything in Egypt. And the movement of the disease into Egypt was just confirmed. Using samples from 2014, three Ug99 races were identified. That event is potentially quite significant, not only for Egyptian wheat production, but for the potential of the disease to now spread into the Mediterranean basin.