A
ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
June 2, 2004
From: Kansas City Star
[edited] <http://www.kansascity.com/mld/kansascity/news/local/8780804.htm>
Mysterious virus appears in wheat fields throughout western
Kansas
An unidentified wheat virus has agricultural scientists in
Kansas scratching their heads. The pathogen causes wheat leaves
to yellow and die, but it's not caused by wheat streak mosaic,
head death or freezing.
"We're pretty sure it's a virus," said wheat breeder Joe Martin,
who works at the Kansas State University research station at
Hays. "It showed up early and, at first glance, we thought it
was wheat streak mosaic. But it's not. It kills the oldest
leaves of the plant and finally kills the head." Researchers
don't know what the virus is, where it came from, or how it
spreads.
Martin said he's seen evidence of the virus in almost every
field he's checked in western Kansas, but it hasn't taken over
the crop. He encouraged farmers to be on the lookout when
checking their fields.
Dallas Seifers, a plant pathology professor at Fort Hays State
University, is trying to determine how the pathogen works, and
what it might be.
"It's possible that this is something that has been identified
somewhere else in the world, even something that has shown up in
a different crop, corn or rice or something," Seifers said.
Seifers, with the help of some virologists in Winnipeg, Canada,
is trying to identify the protein that causes the virus'
symptoms. That work is complicated by the fact that most
affected plants found in the field are already dead. Seifers is
trying to grow his own supply of infected plants to study, but
the effort hasn't been as successful
as he hoped.
Once researchers identify the protein's genetic sequence, they
can compare it to known pathogens to find a match, or one that
is in the same family.
Seifers said it's possible that the virus is showing up now
because of recent unusual weather patterns, and that it wouldn't
show up in a normal year.
"We're just happy that it is not in large enough numbers to have
an economic impact this year, and we hope it will be spotty if
it shows up next year," he said.
[A 28-kD protein has been specifically associated with
infected plants. More research is needed to determine the mode
of spread of the pathogen. Also needed is more information about
the protein and its relationship to disease expression. - Mod.DH] |