Virulent stem rust could wipe out world’s wheatPublished On Tue Oct 5 2010
A virulent strain of stem rust is infecting wheat crops around the world.一稈銹病的劇毒株在感染世界各地的小麥作物。
Debra Black
Staff Reporter
Translation by Autumnson Blog
NOTE: This article has been edited from a previous version.
A form of stem rust, known as Ug99, is threatening the world’s wheat crop – with wheat in Uganda, Kenya, Ethiopia, Iran and South Africa already affected.
稈銹病的一種形式知名為 Ug99真菌，正在威脅著世界的小麥作物 - 在烏干達、肯尼亞、埃塞俄比亞、伊朗和南非的小麥已經受到影響。
Scientists fear the virulent strain is on the move and may show up soon in India and Pakistan. Once there it could be blown by the winds to North America, effecting crops in Canada and the United States, scientists suggest.
科學家擔心毒株在移動，並可能很快在印度和巴基斯坦出現。一旦在那裡便有可能被風吹到北美，影響加拿大和美國的作物，科學家們提出。
While wheat farmers here and in the United States have some options when it comes to planting wheat that is resistant to this form of rust, scientists are also trying to genetically breed new lines that are stronger and even more resistant, said Tom Fetch, stem-rust specialist at Agriculture Canada in an interview with the Star.
當它到種植小麥時，儘管這裡和美國的小麥農民有一些選擇，即是對這種形式的鏽具有抵抗力的，科學家們亦嘗試圖基因培育更強大或甚至更抵抗力強的新品種，在加拿大農業部的幹銹病專家湯姆取在接受星報採訪時說。
Ultimately, the long-term effects could be more devastating in the developing world where, unlike here, many farmers can’t afford to use fungicides to battle the rust, Fetch said.
最終地，長期影響可能在發展中國家是更具破壞性的，不像這裡，許多農民不能負担使用殺菌劑去戰鬥銹病，取說。
According to Martin Carson, research leader at the USDA Cereal Disease Laboratory at the University of Minnesota, 80 per cent of the world’s wheat is susceptible to Ug99, which was found first in Uganda.
Ug99 is a strain of stem rust that burrows into the tissues of wheat and barley, damaging or killing the plant. The fungus saps nutrition from the host plant, he said, absorbing water and putting it under stress. It ends up all shrivelled and shrunken.
Its spread in a field can be rapid. The spores of the fungus germinate and penetrate a plant; in 10 to 14 days, a pustule erupts through the plant and it contains thousands and thousands of spores which can infect more wheat, Carson explained.
Since its discovery in Uganda it has travelled to neighboring countries, wiping out wheat crops, Carson said in an interview with the Star. Now scientists are in “a race against time” to develop new strains that are resistant to the pathogen, he said.
Scientists working at the Durable Rust Resistance in Wheat Project at Cornell University, funded by the Bill and Melinda Gates Foundation, are trying to do just that. But it will likely take between 8 to 10 years to develop a new line and have it ready for planting.
Meanwhile, given wind patterns and where the pathogen has turned up, wheat crops in India and Pakistan may be next hit. But conditions have to be just right for the pathogen to take hold, Carson said.
“It’s a disease where you have to have favourable environmental conditions as well,” he said. “It requires either rainfall or heavy dews for the fungus to penetrate the wheat.” Drought conditions and very high or low temperatures “wouldn’t be particularly favourable.”
If there is a worldwide outbreak affecting the world’s wheat production, it could have some very real “geopolitical repercussions,” including spiking prices for wheat and its products such as bread, Carson said.
He points to 1916 when there was a major outbreak of a kind of stem rust that forced wheat prices to spike at $3 U.S. a bushel then or an equivalent of $60 U.S. a bushel today. It made it very difficult to feed people in Europe after World War 1.
More recently in 2008, when grain prices hit a peak there were food riots throughout North Africa and the Middle East, he said. “In a lot of the world, wheat may be 40 per cent of the caloric daily intake. When you’re living on $2 a day and most of the money goes on food, it doesn’t take much of a rise to spark a riot.
“I think if a lot of people realized how precarious our food supply really is, they might be a little more concerned about some of this stuff.”
With the rust poised to hit India and Pakistan, scientists fear that it won’t be long before it strikes in China. Once there it could blow over to North America on hurricane winds, Fetch explained, and begin to devastate wheat grown in the northern plains of both the U.S. and Canada.
Another more unpredictable fear for scientists is that Ug99 will be brought over to North America on the clothes of someone flying on an airplane from one of the blight-affected regions. The spores are very light and could easily attach themselves to clothing, said Fetch.
The worst thing about this method of transport, he said, is there is no way to predict when or where it might happen.
http://www.thestar.com/news/world/article/870346--virulent-stem-rust-could-wipe-out-world-s-wheat?bn=1
20種跡象：一場可怕的全球性糧食危機在來臨中
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