U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska


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Agricultural Research March 2013


The pale cyst nematode, Globodera pallida, is one bad roundworm.

Unchecked, it invades the roots of potato and other host crops to feed, obstructing the free flow of nutrients and causing stunted growth, wilted leaves, and other symptoms that can eventually kill the plant. Severe infestations in potato fields can cause yield losses of up to 80 percent.

To make matters worse, female G. pallida nematodes form hard, round cysts that safeguard their eggs from predators and parasites, inhospitable conditions, or a scarcity of food. As many as 30 years may pass before the eggs hatch (cued by a signal from their plant host) to spawn a new generation of nematodes to restart the cycle of destruction.

Now, however, a team of ARS and university researchers is working to exploit those plant signals to help counter the emerging threat this pest poses to America’s $3.4 billion tuber crop.

The signals are chemicals—called “egg-hatching factors”—secreted from the roots of potato and some other solanaceous plants into the soil. There, “they penetrate the cysts, stimulating the eggs inside to hatch,” explains Roy Navarre, an Agricultural Research Service plant geneticist with the Vegetable and Forage Crops Research Laboratory in Prosser, Washington. The scientists aim to use the chemicals to trick the eggs into hatching when no potato plants are present, leaving the hatchling nematodes with no host and thus no way to survive.