|Dong, W - UNIV OF GA|
|Brenneman, T - UNIV OF GA|
|Chu, Y - UNIV OF GA|
|Ozias-Akins, P - UNIV OF GA|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 20, 2008
Publication Date: March 15, 2008
Citation: Dong, W.B., Holbrook Jr, C.C., Timper, P., Brenneman, T.B., Chu, Y., Ozias-Akins, P. 2008. Resistance in peanut cultivars and breeding lines to three root-knot nematode species. Plant Disease 92:631-638. Interpretive Summary: Root-knot nematodes causes significant losses to peanut production, and the development and use of resistant varieties is desirable. Three major species of root-knot nematode infect peanut. Sources of resistance to all three nematodes are needed to develop varieties with broad resistance. The objective of this study were to 1) use greenhouse screening and molecular markers to identify new sources of resistance to the three nematodes, and 2) determine the correlation between the resistances to the different species of nematodes. Fifty-seven diverse peanut lines from the U.S. and China were evaluated. Several lines were identified that had either single or multiple resistances to two or all three nematodes. Molecular markers indicated the possible existence of different genes for resistance to the same nematode. The sources of resistance identified in this study should be valuable parents for developing new varieties with broad and durable resistance to root-knot nematode.
Technical Abstract: Three major species of root-knot nematode infect peanut: Meloidogyne arenaria race 1 (Ma), M. hapla (Mh), and M. javanica race 3 (Mj). Sources of resistance to all three nematodes are needed for developing novel peanut cultivars with broad resistance to Meloidogyne spp. Cultivars and breeding lines of peanut were evaluated for resistance to Ma, Mh, and Mj in the greenhouse and in the laboratory. Twenty-six genotypes with some resistance to Ma, Mj, or Mh were identified from 60 accessions based on average eggs/g root and gall index relative to a susceptible control. Among these, fourteen genotypes were moderately to highly resistant to all three species, five genotypes were resistant to Ma and Mj, two genotypes were resistant to Mj and Mh, one genotype was resistant Ma alone, and four genotypes were resistant to Mh alone. Reproduction of Ma on lines NR 0817, C724-19-11, and D108 was highly variable indicating that these genotypes were likely heterogeneous for resistance. COAN, NemaTAM, C724-25-8, and the Ma-resistant plants of C724-19-11 contained the dominant SCAR marker (197/909) for nematode resistance. Results with the molecular markers indicate that the high resistance to Ma in GP-NC WS 6 may be different from the resistance in COAN, NemaTAM, and C724-25-8. Resistance to Ma was correlated with resistance to Mj in peanut, whereas resistance to Mh was not correlated with the resistance to either Ma or Mj. The resistant selections should be valuable sources for pyramiding resistance genes to develop new cultivars with broad and durable resistance to Meloidogyne spp.