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

Abstract

<i>Meloidogyne luci</i> 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 <i>M. ethiopica</i> and <i>M. inornata</i>, and a <i>M. ethiopica</i> group was therefore established. Although specific primers for the DNA amplification of species belonging to the <i>M. ethiopica</i> group have been developed previously, the primers were not species-specific, so molecular markers for the specific detection of <i>M. luci</i> are still needed. The objective of this study was to develop a SCAR marker for the detection of <i>M. luci</i> and the discrimination from other <i>Meloidogyne</i> spp. based on the intraspecific variability found in RAPD markers. RAPD screening of <i>M. luci</i> and <i>M. ethiopica</i> genome was used for the identification of a specific amplification product on <i>M. luci</i>, 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 <i>M. luci</i> isolates with no amplification for the other nine <i>Meloidogyne</i> spp., including <i>M. ethiopica</i> and <i>M. inornata</i>. Additionally, the proper amplification of the <i>M. luci</i> SCAR-marker was also successful with DNA from galls of <i>M. luci</i> infected tomato roots. The results obtained in this study reveal that the specific molecular detection of <i>M. luci</i> was achieved and that the developed methodology can be used for routine diagnosis purposes, which are essential to monitoring the distribution and spread of <i>M. luci</i> in order to implement future effective and integrated nematode pest management programs.