Host Status and Response Differences of Flat-Leaf and Curly-Leaf Parsley to Meloidogyne hapla, M. chitwoodi, M. fallax, and M. incognita Infestation

Abstract

Leaf parsley growth and productivity are often affected by pathogen infection. Root-knot nematodes of the genus Meloiogyne are common pathogens reported on leaf parsley. The response of leaf parsley to Meloidogyne species in tropical and subtropical regions is quite known, while in temperate regions, comparable information is still scarce. In this study, we evaluated the host status and response of three flat-leaf (Laica, Laura, Gigante d’Italia) and three curly-leaf (Grüne Perle, Orfeo, Sombre) parsley cultivars to Meloidogyne species from temperate regions, i.e., M. hapla, M. chitwoodi, and M. fallax, as well as to the southern root-knot nematode M. incognita. Evaluation was based on measuring plant biomass and nematode reproduction nine weeks after nematode inoculation. Our results showed that all four Meloidogyne species did not cause the reduction in leaf parsley growth under the given experimental conditions. Regarding the host status of leaf parsley cultivars for Meloidogyne, results were variable. All six parsley cultivars were found to be good hosts for M. hapla. Regarding M. chitwoodi, the host status could not be clarified properly; however, each cultivar allowed nematode reproduction at least in one experiment. For M. fallax, flat-leaf parsley turned out to be less susceptible than curly-leaf parsley; and for M. incognita, Orfeo, Laura, and Laica were classified as good hosts, Grüne Perle and Sombre as poor hosts, and Gigante d’Italia as a non-host. Amongst all tested cultivars, Gigante d’Italia was found to be the least susceptible cultivar due to its poor host status for M. chitwoodi and non-host status for M. fallax and M. incognita. Infection with M. hapla, M. chitwoodi, and M. incognita, but not with M. fallax, resulted in distinct gall formation on the roots of all six leaf parsley cultivars.