Untapped Hot Pepper Holds Key to Nematode Resistance

The spicy but little-studied Scotch Bonnet pepper may hold the genes that Habanero peppers need to turn up the heat against destructive nematodes.

The nematodes--microscopic wormlike organisms--live in the soil and infect the plants through their roots, sapping yields and sometimes killing plants.

Scientists with USDA’s Agricultural Research Service have found that Scotch Bonnets are an untapped source of genetic resistance to the southern root knot nematode, Meloidogyne incognita. The researchers are breeding this resistance into the more popular Habanero.

The hot Habanero is often used in spicy sauces, seasonings and other food products. Both it and Scotch Bonnet--also a hot pepper--are in the same pepper species, Capsicum chinense.

After tests of approximately 2,000 pepper plants, the researchers have released three lines of nematode-resistant Scotch Bonnet peppers. Seeds of the new lines--known as PA-353, PA-398 and PA-426--have been offered to about 260 seed companies. The seeds are not available for public distribution. Ultimately, the researchers say, seed companies will use the Scotch Bonnets to develop a nematode-resistant Habanero. This would be a first in the annals of hot pepper breeding.

In greenhouse tests with both types of peppers, ARS scientists inoculated the plants with 3,000 nematodes apiece. In the field, they planted peppers in soil already infested with the pests. Two months later, the scientists found that some of the Scotch Bonnets warded off the nematodes. But all the Habanero plants were susceptible.

Habanero seed is available from about 60 seed companies in the United States. Only three companies carry Scotch Bonnets.

Scientific contact: Richard L. Fery, USDA-ARS Vegetable Laboratory, Charleston, S.C., phone (803) 556-0840, fax (803) 763-7013, rfery@awod.com.