Pepper Is Latest Bad News for Nematodes
By Luis Pons
December 19, 2002
Nematode-resistant varieties of
hybrid bell peppers may soon offer desirable characteristics possessed by
nonresistant types. This is because Agricultural Research Service scientists at
the U.S. Vegetable Laboratory
in Charleston, S.C., have bred an experimental hybrid that inherits its
resistance from just one of its parent varieties.
Nematodes are microscopic roundworms that cause millions of dollars in
annual damages to crops nationwide. Root-knot nematodes are a major problem for
bell pepper growers.
The hybrid, developed for research purposes by plant pathologist Judy A.
Thies and geneticist Richard L. Fery, shows that nematode-resistant bell pepper
hybrids can be developed by crossing a resistant, open-pollinated bell pepper
type with varieties lacking the key resistance gene but possessing other
positive characteristics such as large fruits or resistance to disease. The new
hybrid is as resistant as hybrids developed by crossing two resistant pepper
The hybrid marks the latest success from ARS research in nematode-resistant
bell peppers at the Charleston laboratory. In 1997, Fery released Charleston
Belle and Carolina Wonder, the first bell peppers resistant to root-knot
Those peppers' resistance stems from what is called the N gene, which Fery
obtained from Mississippi Nemaheart, a pimiento pepper variety that carries the
resistance gene. The gene controls resistance to three major root-knot nematode
species: Meloidogyne incognita, M. arenaria and M. javanica.
The experimental hybrid was developed by crossing the resistant Charleston
Belle with Keystone Resistant Giant, which lacks the N gene.
Progress with nematode-resistant crop varieties is significant because the
soil fumigant methyl bromide, the primary control method now used to combat the
parasites, is scheduled to be banned in 2005 because of its negative effects on
the ozone layer. A 1995 economic study declared that banning methyl bromide
without an alternative method of controlling nematodes would cost the nation's
bell pepper industry $127 million in losses.
ARS is the chief scientific research agency of the
U.S. Department of Agriculture.