Estimation of population genetic diversity based on mitochondrial DNA analysis of plant-parasitic nematodes Pratylenchus genus (Nematoda: Pratylenchidae)

Root-lesion nematodes of the Pratylenchus are an important pest parasitizing a wide range of vascular plants, including several economically important crops. However, morphological diagnosis of more than 100 species is problematic due to the low number of diagnostic features, high morphological plasticity, and incomplete taxonomic descriptions. In order to employ bar-coding-based diagnostics, we analysed the most important species of Pratylenchus based on COI sequences. Therefore, in 2024, a study was undertaken at the University of Limpopo to estimate population genetic diversity within the Pratylenchus genus based on the cytochrome c oxidase I (COI) region. A total of 73 sequences GenBank were utilized, representing 13 species (Pratylenchus sp., P. zeae, P. parazeae, P. vulnus, P. scribneri, P. brachyurus, P. coffeae, P. loosi, P. horti, P. hippeastri, P. penetrans, P. neglectus, and P. thornei.). The phylogenetic analyses grouped all the species into 14 clades, which separated all species. Haplotype analysis revealed 32 different haplotypes for all species. The average haplotype diversity (Hd) value was 0.96, with high nucleotide diversity (π = 0.29). In conclusion, our results revealed a significant genetic structure among all the species analysed.