From The Viking in the Wheat Field by Susan Dworkin
Ug99, THE WHEAT PLAGUE THAT THREATENS OUR DAILY BREAD
In 1999, at an agricultural field station in Uganda, a scientist noticed something wrong with the wheat.
Pox-like sores had erupted on the stems. They sent forth clouds of reddish orange spores. The scientist correctly concluded that this must be a variety of “rust”, wheat’s most intractable plague.
A fungus disease, rust hitches invisibly on the winds, blowing across international borders, waiting for a down draft or down pour to wash it out of the sky onto the fields. Sometimes it travels on the fur and paws of animals, on the skin or clothing of people. It arrives without notice and seems eventually to target every variety of wheat.
Scientists had not seen a stem rust outbreak for some time. Most kinds of wheat had been imbued by breeders with genes that protected against it. Now suddenly the genes had stopped working. Why? Why were the healthy green fields collapsing, the plants tangled squid-like in a dark, necrotic mass?
Samples of the infected wheat were sent to a lab in South Africa. Scientists there confirmed: this was a new rust, a mutation. It would be named for Uganda, where it was first seen, and 1999, when it was first analyzed. Ug99.
Under carefully controlled conditions the South African lab deliberately spread the disease on samples of local wheat, all of which were equipped with the established defense genes. The wheats should have been resistant. But the great majority sickened.
That was the first and last time UG99 was allowed into South Africa.
Scientists from the Center for Improvement of Maize and Wheat in Mexico, known by its Spanish acronym CIMMYT, (pronounced SIM-mitt) got in touch with the head of the Small Grains Division at the US Agricultural Research Service (ARS) in Beltsville, Maryland: We’ve never seen this stem rust before. It’s virulent for almost all varieties. And it’s moving. We have reports that it has reached Kenya.
The ARS official alerted her colleague in Aberdeen, Idaho, where the United States keeps its national wheat collection. He collected samples of every kind of wheat grown by American farmers, then sent them to the high-security Cereal Disease Lab at the University of Minnesota, the only lab in this country authorized to handle UG99.
There in the dead of winter, when no grain that might be infected was living anywhere in Minnesota, little sacrificial seedlings were doused with UG99. More than eighty per cent of them died.
CIMMYT’s Kenya station reported that the original UG99 had mutated again, overcoming yet another resistance gene. And the plague jumped the Red Sea and invaded Yemen.
What if UG99 reached India and Pakistan, where 50 million small farmers produce 20% of the global wheat supply? CIMMYT pathologists estimated that 97% of the wheat there would succumb. What if it reached the world’s largest wheat producer, China? Then Turkey, France, Kansas? It looked like almost every wheat in the world would have to be re-bred to beat this plague.
And meanwhile, Cyclone Guno hit the Arabian Peninsula, changing the winds and driving Ug99 into Iran.
The breeders, trying to organize themselves into a broad international consortium, had to find new sources of resistance to head off the swiftly mutating rust. In the Olympic winter of 2010, it was one of the most important races being run in this hungry world, and losing it was simply not an option, and most of us had no idea it was even happening. How could we, everyday supermarket shoppers, rolling our carts through the bounteous aisles, even dream that something in the wheat fields might be turning against us, that a small group of scientists from all over the world were now desperately hunting for ways to cure a plague that could profoundly impact our daily bread?
All rights reserved by Susan Dworkin, 2010.
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