World wheat supply threatened

Rust resistant wheatCourtesy USDA - Scott Bauer About a year ago in a Buzz post titled "Wheat futures" I expressed concern about the world's vulnerability to a wheat fungus called Ug99.

When wheat rust hit the North American breadbasket, in 1954, it wiped out 40 per cent of the crop. Norman Borlaug solved that wheat rust problem and earned a Nobel Prize by developing wheat that resisted stem rust.

About 10 years ago we identified a new stem rust in Uganda (that's why it's called Ug99) that is a mutation with the ability to once again wipe out more than 90 percent of the world's wheat varieties. This new variety of wheat rust has already spread from eastern Africa into Iran. It can then travel via Afghanistan to Pakistan into India and then China. We are lucky that a drought in Iran has slowed the successful propagation of the fungus spores.

Progress against wheat rust reported

At a workshop this week sponsored by Borlaug Global Rust Initiative more than 200 crop scientists from around the world discussed their efforts to crossbreed wheat varieties resistant to the new, virulent type of rust fungus.

The researchers led by Singh, of the Mexico-based International Maize and Wheat Improvement Center, have engaged in "shuttle" crossbreeding of wheat varieties in the search for Ug99-resistant properties, developing varieties in test fields in Mexico and Syria, exposing them to Ug99 in Africa, returning them for refinement, then exposing them again in Africa.
The resistance comes not from one or two genes that convey immunity, but from an array of "multiple minor genes" that together achieve "near-immunity" Scientific American

Multiplication of seed takes about 5 years

Last summer about 3.5 tons of resistant seed was grown (a total of 12 resistant lines). This seed has been sent to seven countries including Turkey. Those lines will produce all together several hundred tons of seed in these countries.

What we really need, what we really pray for, is another three to four years where the environment is not conducive to a stem rust epidemic. Then we would have sufficient varieties out there to avoid disaster.

Sources
New Wheat Strain Could Cut Fungus Threat: New York Times

Global Wheat Crop Threatened by Fungus: A Q&A with Han Joachim Braun Scientific American

Scientists gain in struggle against wheat rust Associated Press