In 2013, during a field survey conducted in Portugal on potato, Solanum tuberosum , an unusual esterase ( EST ) phenotype was detected in a root‐knot nematode ( RKN ) from potato roots collected in Coimbra. This Portuguese isolate was purified and maintained on tomato, S. lycopersicum , and morphological, biochemical and molecular characteristics were studied. Perineal pattern morphology was highly variable, similar to Meloidogyne ethiopica and not useful for identification. The EST phenotype, from young egg‐laying females, displayed three bands similar to the Brazilian M. luci (L3) and distinct from M. ethiopica (E3). Phylogenetic analyses of mitochondrial cytochrome oxidase subunit I and the mitochondrial DNA region between COII and 16S rRNA genes revealed that the Portuguese isolate grouped with M. luci isolates close to M. ethiopica isolates. However, considering the ITS 1‐5.8S‐ ITS 2 region, the Portuguese isolate grouped with isolates of M. luci , M. ethiopica and M. hispanica , which limits the confidence of this region for M. luci diagnosis, and its differentiation from other species with morphological similarities. The M. luci pathogenicity to potato was also assessed in 16 commercial cultivars and compared with M. chitwoodi , considered to be a quarantine RKN species by EPPO . All potato cultivars were susceptible to both Meloidogyne species with gall indices of 5 and higher reproduction factor values ranging from 12.5 to 122.3, which suggests that M. luci may constitute a potential threat to potato production. In the present study, M. luci is reported for the first time attacking potato in Portugal.

Meloidogyne luci has been identified in various countries around the world parasitizing economically important crops and, due to its potential to cause serious damage to agriculture, was included in the European and Mediterranean Plant Protection Organization Alert List in 2017. This species shares morphological and molecular similarities with M. ethiopica and M. inornata, and a M. ethiopica group was therefore established. Although specific primers for the DNA amplification of species belonging to the M. ethiopica group have been developed previously, the primers were not species-specific, so molecular markers for the specific detection of M. luci are still needed. The objective of this study was to develop a SCAR marker for the detection of M. luci and the discrimination from other Meloidogyne spp. based on the intraspecific variability found in RAPD markers. RAPD screening of M. luci and M. ethiopica genome was used for the identification of a specific amplification product on M. luci, which was cloned, sequenced and converted into a SCAR marker. The specificity of the designed primers (Mlf/r) was tested and produced a fragment (771 bp) for all nine M. luci isolates with no amplification for the other nine Meloidogyne spp., including M. ethiopica and M. inornata. Additionally, the proper amplification of the M. luci SCAR-marker was also successful with DNA from galls of M. luci infected tomato roots. The results obtained in this study reveal that the specific molecular detection of M. luci was achieved and that the developed methodology can be used for routine diagnosis purposes, which are essential to monitoring the distribution and spread of M. luci in order to implement future effective and integrated nematode pest management programs.