Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/27/1999
Publication Date: N/A
Citation: N/A Interpretive Summary: Four species of root-knot nematodes (Meloidogyne incognita, M. javanica, M. arenaria, and M. hapla) are major pests in pepper growing areas of the United States. Pre-plant soil fumigation with methyl bromide is currently the primary control method for root-knot nematodes in bell pepper, but the proposed cessation of importation and production of this fumigant in the United States on 1 January 2001 has focused significant interest on host plant resistance. Recently, Charleston Belle and Carolina Wonder, the first bell pepper cultivars with resistance to the southern root-knot nematode (M.incognita), were developed and released by scientists at the U.S. Vegetable Laboratory, USDA, ARS, Charleston, S.C. These cultivars provide an alternative to pre-plant fumigation of soil with methyl bromide for managing the southern root-knot nematode. However, the reaction of these resistant cultivars to the other major species of root-knot nematodes is unknown. We determined that the N gene, which conditions resistance to M. incognita, also conditions resistance to M. arenaria races 1 and 2 and M. javanica, but not to M. hapla. Information on this resistance in pepper is important for making varietal recommendations and for designing cropping systems to manage root-knot nematodes, and in setting future priorities for pepper breeding programs.
Technical Abstract: Two isogenic sets of pepper (Capsicum annuum L.) lines (isogenic at the N root-knot nematode resistance locus) were characterized for resistance to Meloidogyne arenaria races 1 and 2, M. hapla, and M. javanica in greenhouse and growth chamber tests. The isogenic sets of C. annuum were 'Charleston Belle' (NN) and 'Keystone Resistant Giant' (nn - recurrent parent), and 'Carolina Wonder' (NN) and 'Yolo Wonder B' (nn - recurrent parent). Meloidogyne arenaria race 1 is pathogenic to C. annuum. 'Charleston Belle' and 'Carolina Wonder' exhibited high resistance to M. arenaria race 1 and their respective recurrent backcross parents 'Keystone Resistant Giant' and 'Yolo Wonder B' were susceptible. Meloidogyne arenaria race 2 and M. javanica are not highly pathogenic to pepper. However, 'Charleston Belle' and 'Carolina Wonder' both exhibited higher (P<0.05) resistance to M. arenaria race 2 and M. javanica than 'Keystone Resistant Giant' and 'Yolo Wonder B'. Meloidogyne hapla is pathogenic to pepper. Both 'Charleston Belle' and 'Carolina Wonder' and their respective recurrent parents 'Keystone Resistant Giant' and 'Yolo Wonder B' were susceptible to M. hapla. We concluded that the N gene confers resistance to M. arenaria races 1 and 2, and M. javanica in C. annuum, but the N gene does not condition resistance to M. hapla.