Response of mint varieties from Central Europe (Mentha spp.) to Meloidogyne infestation

Mentha is a cosmopolitan genus of medicinal and aromatic plants, which is characterised by the essential oils in its leaves and its therapeutic and aromatic qualities. Mint species are usually cultivated as a perennial crop and therefore susceptible for various pests and diseases. Root-knot nematodes of the genus Meloidogyne are one of the pathogens that can reproduce on mint and cause plant growth reduction. To better understand the pathogenicity of Meloidogyne on mint we studied whether an increasing number of Meloidogyne affects plant growth and essential oil content in the leaves. For our greenhouse experiments, we selected peppermint (Mentha x piperita ˈMultimenthaˈ) as the major mint variety cultivated in Central Europe and the root-knot nematode M. hapla that can pose a major threat in temporal regions. In addition, we evaluated the pathogenicity and reproduction of M. chitwoodi, M. fallax and M. incognita on peppermint and other commonly grown mint varieties in Central Europe, i.e. Mentha x piperita ˈFränkische Blaueˈ, apple mint (M. rotundifolia) and spearmint (M. spicata). None of the studied root-knot nematode species had a negative impact on plant growth of peppermint ˈMultimenthaˈ. However, high densities of M. hapla caused a reduction in the essential oil content. In conclusion, peppermint ˈMultimenthaˈ turned out to be a good host for M. hapla, but a non-host for M. chitwoodi, M. fallax and M. incognita. Plant growth of all four mint varieties was not affected by M. hapla infestation. In addition, peppermint ˈMultimenthaˈ and spearmint were more susceptible to M. hapla than apple mint and peppermint ˈFränkische Blaueˈ.