Developments in Brief : Potato Hybrid Provides Own Insect Repellent

U.S. Agriculture Department scientists have developed the first hybrid potato plant with its own built-in insect repellent, a development that eventually may lead to commercial development of insect-resistant potatoes.

Stephen L. Sinden said the two-year project involved fusing together single cells from wild and commercial potato plants, then regrowing the hybrid plants from the fused cells.

He said the hybrid potatoes contain a rare gene for leptine, a chemical that repels insects. The leptine was passed on from the wild plant.

“The most devastating pest of U.S. potato fields, the Colorado potato beetle, is repelled by leptine,” Sinden said. “The beetles land on the hybrid plants as usual. They peel back a little skin on leaves and nibble, but then fly away. The plants are barely touched.”

Beetles in recent years have developed a tolerance to chemicals farmers use to spray potato fields, operations that cost more than $120 million a year, Sinden said.

Further tests are set for this summer to check the hybrids for resistance to other insects, such as troublesome potato leafhoppers.

Cell fusion used to develop the hybrid potato is a form of genetic engineering in which the DNA, or hereditary molecules, remains intact.

Leptine may be toxic to humans in large doses, Sinden said. However, the hybrid plants make leptine only in the leaves, not in the potatoes.

The hybrid plants produce much larger potatoes than the wild plants and are at least half the size of commercially grown potatoes now available, he said.