Species-Specific Molecular Detection of the Root Knot Nematode Meloidogyne luci

SIMPLE SUMMARY: The root knot nematode Meloidogyne luci has been identified in various countries around the world parasitizing economically important crops. Due to its potential to cause serious damage to agriculture, the need for an accurate diagnosis at the species level has become mandatory. In the present study, a specific amplification product on M. luci was obtained from a random amplified polymorphic DNA (RAPD) analysis. The DNA was sequenced and converted into a sequence characterized amplified region (SCAR) marker used for the species-specific molecular detection of this root knot nematode. The developed methodology is essential to monitoring the distribution and spread of M. luci in order to implement future effective and integrated pest management programs. ABSTRACT: 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.