Very good news from the United States Department of Agriculture. Breeders are about to release the first wheat lines that incorporate several genes for resistance to UG99, the new race of rust fungus that threatens wheat worldwide. One line will be available to growers on the east coast of the US. All will be available to breeders worldwide to develop new varieties adapted to local conditions.
Part of the effort leading to the new wheats has been a screening of more than 5000 accessions from several genebanks. One outcome of this massive evaluation exercise has been the discovery that UG99 had overcome many more resistance genes than original estimates. That’s why it has been important to pyramid several resistance genes into the new varieties. Just where those resistance genes came from I don’t know. But the USDA does say that the breeders “also will develop new sources of genetic resistance to rusts from three wild relatives of wheat”.
Good luck to them. Certainly the wheat farmers of Iran, Pakistan, Afghanistan and northern India — the current front in the fight against UG99 — need all the help they can get. But a tiny part of me really rather hopes that the new varieties are not in fact a success.
The world badly needs another demonstration of the power of pests and diseases to destroy food supplies and the importance of agricultural biodiversity to protect us from them. Southern corn blight is the poster child for the value of diversity.
That outbreak more or less created the modern move to conserve crop diversity in genebanks, a move that has lost its impetus as the world forgets that food security requires the ready availability of lots and lots of agricultural biodiversity.
So while I am truly glad that breeders are making progress against UG99, I’d also like to see UG99 make real inroads into the developed world’s wheat crops, just as a reminder, lest they forget.