Development of a PCR‐Based Molecular Marker to Select for Nematode Resistance in Peanut

Abstract

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 random amplified polymorphic DNA (RAPD) 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 phenotype 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.