Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2006
Publication Date: 3/1/2007
Citation: Chu, Y., Holbrook Jr, C.C., Timper, P., Ozias-Akins, P. 2007. Development of a PCR-based Molecular Marker to Select for Nematode Resistance in Peanut. Crop Sci. 47:841-845.
Interpretive Summary: The root-knot nematode causes serious yield losses in peanut. The development of peanut varieties with resistance to this nematode would reduce yield losses while reducing the use of nematicides in fields where these nematodes occur. The identification and refinement of molecular marker for use in marker assisted selection would improve the efficiency of identifying resistant plants, and speed breeding efforts to combine nematode resistance with other important characteristics in peanut. Our research resulted in the development of a molecular marker that is reproducible and highly correlated with nematode resistance. This marker is economical to use and can be used in a high-throughput DNA extraction method. Plant breeders will be able to use this new marker to hasten efforts to combine nematode resistance with other important characteristics in peanut.
Technical Abstract: The peanut root-knot nematode (Meloidogyne arenaria (Neal) Chitwood race 1) is a significant pathogen on peanut (Arachis hypogaea L.). Nematode-resistant cultivars would reduce yield losses while reducing the use of nematicides in fields where these nematodes occur. Through years of breeding effort, nematode resistance gene(s) have been introgressed into peanut cultivars from their wild relatives, Arachis spp. Molecular markers RKN440 and Z3/265, linked to the resistance gene, previously were identified by RAPD (random amplified polymorphic DNA) analysis. Unfortunately, when these markers were applied to our breeding programs, neither could give a reproducible level of correlation with the phenotype data. In this study, we modified the marker RKN440 based on more complete sequencing data and established a new nematode-resistance dominant marker 197/909. This marker is reproducible and shows a high correlation with the phenotypic data. It amplifies fragments from both susceptible and resistant samples, but of different molecular weights, avoiding false negative judgment caused by failed reactions with dominant markers. When we applied this marker using a cost-effective, high-throughput DNA extraction method, it remained a robust assay. Plant breeders will be able to use this new marker to hasten efforts to combine nematode resistance with other important characteristics in peanuts.