Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2000
Publication Date: 9/1/2000
Citation: Fery, R.L., Thies, J.A. 2000. Inheritance of resistance of the peanut root-knot nematode in hot pepper (capsicum chinense). Journal of the American Society for Horticultural Science. 125(5):615-618. Interpretive Summary: Although varieties belonging to the species Capsicum annuum account for most of the peppers grown in the United States, two types of peppers (Habanero and Scotch Bonnet) belonging to the species C. chinense are becoming common because of the increasing popularity of extremely pungent peppers. The peanut root-knot nematode (Meloidogyne arenaria) has numerous crop hosts, is widely distributed throughout the southern U.S., and can be highly pathogenic on C. chinense. USDA, ARS scientists have identified several C. chinense germplasm lines that exhibit a high level of resistance. Because the efficient and effective use of any pest resistant germplasm in a plant breeding program is dependent upon an understanding of the inheritance of the trait, this study was initiated to determine the inheritance of peanut root-knot nematode resistance in C. chinense. The results of this study demonstrated that resistance to the peanut root-knot nematode in C. chinense is controlled by a single dominant gene. This means that the development of peanut root-knot nematode resistant varieties of C. chinense is a very feasible objective for a pepper breeding program. The availability of resistant varieties would eliminate the need to use pesticides to control peanut root-knot nematodes in C. chinense plantings.
Technical Abstract: Greenhouse experiments were conducted to determine the inheritance of resistance to the peanut root-knot nematode [Meloidogyne arenaria (Neal) Chitwood race 1] exhibited by the Capsicum chinense Jacq. germplasm lines PA-353 and PA-426. Evaluation of parental, F1, F2, and backcross populations of the crosses PA-353 x PA-350 and PA-426 x PA-350 (PA-350 is a susceptible cultigen) indicated that the resistance in both C. chinense germplasm lines is conditioned by a single dominant gene. Evaluation of the F1 x resistant parent backcross populations in the cytoplasm of their respective resistant and susceptible parents indicated that the cytoplasm of the resistant parent is not needed for full expression of resistance. The results of allelism tests indicated that the dominant resistance gene in both PA-353 and PA-426 is allelic to a resistance gene in the C. annuum L. cv. Carolina Cayenne. However, these allelism tests did not demonstrate conclusively that the M. arenaria race 1 resistance gene in C. chinense is the N gene that conditions resistance to the southern root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] in C. annuum. The availability of simply inherited sources of resistance makes breeding for peanut root-knot nematode resistance a viable objective in C. chinense breeding programs.