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.
