Detection of the camellia root-knot nematode Meloidogynecamelliae Golden in Japanese camellia bonsai importedinto Italy: integrative diagnosis, parasitic habits andmolecular

Abstract The camellia root-knot nematode Meloidogyne camelliae was detected in Italy parasitizing roots of Japanese camellia (Camellia sasanqua) flowering bonsai trees imported from Japan, and it represents a new record for Europe. Morphology and morphometrical traits analysis of the intercepted population of M. camelliae were in agreement with those of the original description of the species, except for some minor differences in second-stage juvenile stylet length and c ratio, spicules and gubernaculum in males, which may be a result of intraspecific variability. Integrative molecular data for this species were obtained using D2-D3 expansion segments of 28S rDNA, ITS1-rDNA, and the protein-coding mitochondrial gene COI. The phylogenetic relationships of this species with other representatives of Meloidogyne spp. using D2-D3 expansion segments and ITS1 indicated that M. camelliae clustered together with M. artiellia and M. baetica. Histological observations of C. sasanqua feeder roots infected by M. camelliae reveal slight swellings of the root feeding sites, and most egg-laying females protruding from the root. The anatomical alterations at feeding sites consist of 3-8 hypertrophied, polinucleate giant cells/female, but no hyperplasia was induced unlike what commonly occurs for most members of the genus.