Root-knot nematodes from the genus Meloidogyne are polyphagous plant endoparasites and agricultural pests of global importance. Here, we report the high-quality genome sequence of Meloidogyne luci population SI-Smartno V13. The resulting genome assembly of M. luci SI-Smartno V13 consists of 327 contigs, with an N50 contig length of 1,711,905 bp and a total assembly length of 209.16 Mb.

Root-knot nematodes are considered the most important group of plant-parasitic nematodes due to their wide range of plant hosts and subsequent role in yield losses in agricultural production systems. Chemical nematicides are the primary control method, but ecotoxicity issues with some compounds has led to their phasing-out and consequential development of new control strategies, including biological control. We evaluated the nematicidal activity of Bacillus firmus I-1582 in pot and microplot experiments against Meloidogyne luci. I-1582 reduced nematode counts by 51% and 53% compared to the untreated control in pot and microplot experiments, respectively. I-1582 presence in the rhizosphere had concurrent nematicidal and plant growth-promoting effects, measured using plant morphology, relative chlorophyll content, elemental composition and hyperspectral imaging. Hyperspectral imaging in the 400–2500 nm spectral range and supervised classification using partial least squares support vector machines successfully differentiated B. firmus-treated and untreated plants, with 97.4% and 96.3% accuracy in pot and microplot experiments, respectively. Visible and shortwave infrared spectral regions associated with chlorophyll, N–H and C–N stretches in proteins were most relevant for treatment discrimination. This study shows the ability of hyperspectral imaging to rapidly assess the success of biological measures for pest control.

Root-knot nematodes (Meloidogyne spp.) are considered the most aggressive, damaging, and economically important group of plant-parasitic nematodes and represent a significant limiting factor for potato (Solanum tuberosum) production and tuber quality. Meloidogyne luci has previously been shown to be a potato pest having significant reproductive potential on the potato. In this study we showed that M. luci may develop a latent infestation without visible symptoms on the tubers. This latent infestation may pose a high risk for uncontrolled spread of the pest, especially via seed potato. We developed efficient detection methods to prevent uncontrolled spread of M. luci via infested potato tubers. Using hyperspectral imaging and a molecular approach to detection of nematode DNA with real-time PCR, it was possible to detect M. luci in both heavily infested potato tubers and tubers without visible symptoms. Detection of infested tubers with hyperspectral imaging achieved a 100% success rate, regardless of tuber preparation. The real-time PCR approach detected M. luci with high sensitivity.

Bacillus firmus nematicidal bacterial strains are used to control plant parasitic nematode infestation of crops in agricultural production. Proteases are presumed to be the primary nematode virulence factors in nematicidal B. firmus degrading the nematode cuticle and other organs. We determined and compared the whole genome sequences of two nematicidal strains. Comparative genomics with a particular focus on possible virulence determinants revealed a wider range of possible virulence factors in a B. firmus isolate from a commercial bionematicide and a wild type Bacillus sp. isolate with nematicidal activity. The resulting 4.6 Mb B. firmus I-1582 and 5.3 Mb Bacillus sp. ZZV12-4809 genome assemblies contain respectively 18 and 19 homologs to nematode-virulent proteases, two nematode-virulent chitinase homologs in ZZV12-4809 and 28 and 36 secondary metabolite biosynthetic clusters, projected to encode antibiotics, small peptides, toxins and siderophores. The results of this study point to the genetic capability of B. firmus and related species for nematode virulence through a range of direct and indirect mechanisms.

Root-knot nematodes (RKN) of the tropical group reproducing as a rule with mitotic parthenogenesis are highly polyphagous and damaging pests causing great losses in crop production. Morphometrical and molecular characters of three closely related tropical RKN species have been analysed in order to identify species-specific diagnostic parameters and examine the relationship between species. Morphometrical characters of M. ethiopica, M. luci and M. inornata isolates were similar and overlapped when compared between species and isolates of the same species indicating a very close relationship between the three species. Additionally, structure of map-1 genes was analysed, which provided the evidence of identical structure of map-1 family genes in M. ethiopica, M. inornata and M. luci. The unique structure of map-1 genes when compared to the other tropical RKN species further supports close relationship of the three species and therefore we have classified them together as M. ethiopica group. In addition, our results showed that the emergence of a virulent M. luci population does not correlate with the loss of map-1 genes as it was previously indicated for M. incognita (Castagnone-Sereno et al. 2009 ). Further, we have developed novel molecular methods to aid in identification of these nematodes: a PCR based method with primers specific for the M. ethiopica group comprising M. ethiopica M. luci and M. inornata, and a PCR based method with primers specific for the tropical RKN group species. Our results show that species of Meloidogyne ethiopica group share high similarity at morphological and genetic level.

The plant parasitic nematode Meloidogyne ethiopica Whitehead has been reported from several European countries including Slovenia, where it was first found in 2003. However, the description in 2014 of a new sister species, Meloidogyne luci Carneiro et al., , called for the reclassification of all European and Turkish populations of M. ethiopica reported up to this date as M. luci. Both M. ethiopica and M. luci have a very wide host range of monocotyledons and dicotyledons. They are pests of important agricultural crops such as maize, potatoes and variety of vegetables, and represent a serious threat for agricultural production in greenhouses as well as in the open fields in many EPPO countries. This paper reports a new location for the tropical root knot nematode species M. luci found in Slovenia in 2015.