Scientists Seek New Ways to Control Potato
Pests By Ann
Perry August 29, 2007
New and more virulent forms of two scourges that rampaged through
potato fields in the pastthe golden nematode (Globodera
rostochiensis) and potato virus Y (PVY)are making a comeback. But
Agricultural Research Service (ARS)
scientists are catching up to them.
Twenty years ago, stringent controls eventually confined the golden
nematodealso called the potato cyst nematodeto several counties in
New York, where it was first discovered. However, more than 30 varieties of
potatoes that were previously nematode-resistant are now vulnerable to attack
from a new race of the golden nematode, dubbed "Ro2."
Wang, a molecular biologist in the Plant Protection Research Unit (PPRU) at
Ithaca, N.Y., is using molecular biology techniques to study specific parts of
Ro2 DNA. This will help speed its field identification. She is also looking for
ways to increase potato resistance to Ro2 using a method called RNA
interference (RNAi), which interferes with gene expression.
A pathogen of potatoes as well as tomatoes, peppers and tobacco, PVY
dramatically affects produce yield and quality. Although seed potatoes are
screened for PVY, its resurgence is due in part to varieties that are
symptomless carriers of the virus. Some PVY strains have also become more
virulent over time.
Gray, also at the PPRU, is coordinating a survey of all U.S. potato
seed-production areas to determine PVY's genetic diversity and distribution in
the United States. This is one part of a plan developed by an international
team of scientists, regulatory personnel and industry representatives to manage
potato viruses that result in tuber necrosis. These strategies will help stem
the spread of PVY, and should help prevent necrotic PVY strains from becoming
predominant in North America.
ARS research on these pathogens will help the potato industry remain
viable and boost producer efforts to expand their markets.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.
more about this research in the August issue of Agricultural Research