Plagues,
Pestilences and Diseases
New Zealand: Deadly Kiwifruit disease traced to China
by Staff Writers
Washington (AFP) May 9, 2012
US and Italian scientists have traced a bacterium that has been
destroying kiwifruit in New Zealand and Europe back to China where
they believe it originated, according to a study on Wednesday.
Since the disease known as "kiwifruit canker" emerged in Italy
2008, it has wiped out orchards mainly across Europe and South
America and caused hundreds of million of dollars in losses,
according to the article in the journal PLoS ONE.
The culprit is a bacterium, Pseudomonas syringae pv. actinidiae
(Psa), which causes red or white slime to ooze from the plant's
stems or branches, in some cases causing the plants to die.
A similar disease afflicted orchards in China and Japan in the
1980s, so scientists used the latest DNA sequencing technology to
shed light on the pathogens to see if there were any links.
Virginia Tech associate professor Boris Vinatzer and Giorgio
Balestra of the University of Tuscia in Italy sequenced the DNA of
Psa bacteria from kiwifruit trees in China, Italy, New Zealand and
Portugal.
They found that the bacteria from China, Europe, and New Zealand
were almost identical, with one slight variation that in a single
region of the DNA that linked the New Zealand outbreak to the
Chinese bacteria.
Therefore, the study authors believe the bacterium was likely
imported from China to Italy first, and later from China into New
Zealand where the disease turned up in 2010.
"The first step in stopping the spread of aggressive bacteria like
Psa is knowing where they come from and how they have spread,"
Balestra said.
"Now that we have sequenced the DNA and found its likely origin,
we can start to figure out ways to stop it and similar bacteria
from doing so much damage in the future."