The Status of Root-Knot Nematodes of the Meloidogyne Genus in Croatia, with a Special Reference to the Quarantine Species

Abstract

Root-knot nematodes of the genus Meloidogyne belong to the most economically important group of plant-parasitic nematodes and also to the most important plant pests that can cause significant economic losses in crop production. They are poly phagous, highly adapted, obligate endoparasites of nearly all higher plant species, including the important agricultural crops. Within the genus Meloidogyne, about one hundred species have been described, of which the four species-that is, the Meloidogyne incognita, M. arenaria, M. javanica, and M. hapla-are the important plant pests and the most widespread species worldwide. As of 2010, twenty-three species have been confirmed in Europe, of which three non-quarantine species have been detected in Croatia. Many nematode species of the genus Meloidogyne can be considered dangerous invasive pests in agriculture, as they can spread rapidly due to the global trade, changing production technologies leading to a reduced use of pesticides, and climatic changes. To prevent or to limit the introduction and spread of the three species of root-knot nematodes, Meloidogyne chitwoodi, M. fallax, and M. enterolobii, respectively, were entered in the European list of quarantine nematodes. The species M. mali is incorporated in the EPPO A2 quarantine list, in addition to the three aforementioned species, while the M. ethiopica, M. luci, and M. graminicola are on the EPPO Alert List. It is expected that the tropical Meloidogyne species, for instance the M. enterolobii, M. ethiopica, and M. luci, as well as the M. incognita, M. arenaria, and M. javanica, will become the important pests in the temperate zones due to the new,) climatic conditions, more favorable for their development, which can pose a huge risk to the agricultural production. In Croatia, a wide distribution of nematode populations of the genus Meloidogyne spp. was con firmed, but a scientific knowledge about the species identification is very modest. Due to the variety of soil and climatic conditions present in Croatia, it is expected that more Meloidogyne species than those that are known so far will be detected in the future. This is one of the reasons for starting a more intensive monitoring of the Meloidogyne species in Croatia too.