by Juma Kwayera
African crop scientists attending a conference in the Mexican town of Ciudad Obregon said they have made a breakthrough in developing wheat varieties that are resistant to wheat plague.
According to a statement on the new study findings at the conference, researchers from the Kenya Agricultural Research Institute (KARI) and the Ethiopian Institute for Agricultural Research (EIAR) announced a breakthrough in their “efforts to develop new varieties of wheat that are not only resistant to Ug99, but also produce more grain than today’s most popular varieties.”
The research findings were backed by Mexico-based International Maize and Wheat Improvement Centre, known by its Spanish acronym CIMMYT (or Centro Internacional de Mejoramiento de Maíz y Trigo) and Syria-based International Centre for Agricultural Research in the Dry Areas (ICARDA).
Every region of the world is represented at the meeting in Ciudad Obregón, organised by the Borlaug Global Rust Initiative.
Mr Ravi Singh, a CIMMYT wheat geneticist and pathologist and lead author of the study, is quoted in the statement as saying that high-yielding, Ug99-resistant spring wheat varieties are rapidly emerging through an intensive international “ shuttle-breeding programme.”
“Breeding materials under development in CIMMYT’s test fields in Ciudad Obregón and Toluca and at ICARDA fields in Aleppo, Syria, are sent to Kenya and Ethiopia, where they are exposed to Ug99 in real world conditions. They are then sent back to Mexico or Syria for further refinement and then back to Kenya and Ethiopia for more exposure,” the statement said.
Through this approach, scientists who also shuttle between continents have produced new types of high-yield wheat that contains what plant breeders call “multiple minor genes” that have resistance to Ug99.
“Although this strategy may not provide the same level of protection as that provided by one or two major genes, it is high enough to be effective, and the rese a rchers believe that by forcing the fungus to overcome a larger array of genetic barriers, these new wheat varieties could provide long-term protection against future stem rust mutations,” it added.
There are numerous examples in the last century of stem rust mutating and “defeating” wheat plants that have contained single major resistance genes.
The statement cited “the alarming hallmarks of Ug99, (which) in Kenya has mutated and overcome two additional major stem rust resistance genes called Sr24 and Sr 36 that had been effective against the original form of Ug99.”
“We believe that this approach of endowing a plant with many minor resistance genes in combination can provide resistance comparable to the best single major resistance gene, giving us the potential to end this dangerous arms race against wheat stem rust,” Singh was quoted as saying, noting also that many countries have contributed plant materials and expertise to the programme.
Afriquejet