Detection of Meloidogyne enterolobii in potatoes in South Africa and phylogenetic analysis based on intergenic region and the mitochondrial DNA sequences

Abstract

Root-knot nematodes (Meloidogyne spp.) are a major problem facing crop production globally including potatoes. During the 2011/2012 potato growing season, root-knot nematode infested potato tubers were obtained from different potato growing regions in South Africa for identification of Meloidogyne spp. Using the intergenic region of the ribosomal DNA (IGS-rDNA) together with the region between the cytochrome oxidase small subunit II (COII) and the 16S rRNA gene in the mitochondrial DNA (mtDNA), five of the 78 composite samples received produced amplicon sizes of 705bp for COII and 780bp for IGS typical of M. enterolobii. These five samples were from the KwaZulu-Natal potato producing region. Nucleotide sequencing and phylogenetic analysis of the COII and IGS fragment showed that the five Meloidogyne populations were 100% similar and they clustered closely with those of M. enterolobii in the GenBank database. The high damage potential of resistance-breaking populations of Meloidogyne species is a threat to profitable potato production and will require effective pest management programmes to be put in place.