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Nematodes of the genus Xiphinema (dagger nematodes) are migratory root ectoparasites with a broad host range. There are more than 260 species, of which approximately 60 belong to the Xiphinema americanum group (X. americanum sensu lato). Some of the species can specifically transmit certain nepoviruses of phytosanitary concern. Several subgroups of nepoviruses exist, each with their own specific vector species. Based on morphological and morphometrical data, the identification up to Xiphinema species level is quite difficult. Most of the time, it is impossible due to lack of specimens or appropriate nematode stadia. Currently, there is also a lack of molecular information of all Xiphinema species to develop reliable diagnostic tools such as PCR or barcoding. Direct damage caused by Xiphinema species is usually limited, the main issue is that some specimens are potential carriers of viruses. Whereas the whole X. americanum group had a quarantine status before the new Plant Health Legislation (December 2019), only 7 species retained this status and two species became regulated non-quarantine organisms. Still, their identification up to species level is very difficult. Focusing on a direct detection of these viruses in the nematodes could be an alternative to the difficult task of correctly identifying the Xiphinema species. This way, only specimens of the X. americanum group that are actually carrying viruses can be considered as a Plant Health risk, and consignments carrying Xiphinema spp. free of viruses could be allowed to enter trade. The aim of the project was to optimise a generic classic nepovirus detection test for nematodes of the genus Xiphinema and ultimately to validate it through the organisation of an interlaboratory test. Based on literature, methods were selected to develop a diagnostic procedure for nepovirus detection in Xiphinema nematodes. Nematodes (X. diversicaudatum, X. index, and X. americanum s.s.) and nepoviruses (Arabis mosaic virus (ArMV), grapevine fanleaf virus (GFLV) and tomato ringspot virus (ToRSV)) were procured, virus transmission assays were carried out and the selected methods were compared and validated in the laboratory. This resulted in a recommended diagnostic protocol consisting of the Automated Zonal Centrifuge (AZC) for nematode extraction from soil, a method of choice for physical disruption of the isolated nematodes (slicing, bead beating and bead beating with collagenase pre-treatment) and the KingFisher MagMax Kit for RNA extraction. Due to inadequate sensitivity of generic nepovirus subgroup detection tests, nepovirus detection still relies on specific single nepovirus real-time PCR tests. The MinION nanopore technology was evaluated as an alternative for the future. MinION nanopore sequencing failed to detect GFLV and ToRSV in single nematode specimens. However, its potential was demonstrated by successful ArMV detection in six X. diversicaudatum individuals.

Success story of the Euphresco project 2018-A-293 'Phytosanitary risks of newly introduced crops (PRONC)'

Slide of the Euphresco project 2020-A-334 'Plant health status of Fagus spp. (FAGUSTAT)', Project funded through the Euphresco network

Slide of the Euphresco project 2019-A-330 'Detecting virus-carrying Xiphinema spp. as an alternative to Xiphinema identification up to species level in trade (XiphiVIR)', Project funded through the Euphresco network

Slide of the Euphresco project 2018-A-293 'Phytosanitary risks of newly introduced crops (PRONC)', Project funded through the Euphresco network

During the Greenresilient project, nematode communities will be characterized at the beginning, in the middle and at the end of the field trials to identify shifts in their community. These shifts will be analysed to determine whether the chosen ‘innovative’ methods tested in the project are beneficial for soil health, causing an increased resilience to pests and diseases and a more balanced nutrient supply, for more sustainable and high-quality crop production. This leaflet explains why nematodes can be excellent indicators for soil health.

Nigeria is the main yam-growing country of the world. In the country, various plant-parasitic nematodes have been reported constraining yam production and the storability of tubers. This study established the damage level of nematodes on white yam tubers (Dioscorea rotundata) across the major production areas in the country for management purposes. Incidence and severity of symptoms (cracking, dry rot, and galling) associated with nematodes were assessed on 1,114 yam heaps (181 vendors) from 23 markets and on 2,502 tubers from 26 farmer storage areas (yam barns) in the Humid Forest (HF), Derived Savanna (DS) and Southern Guinea Savanna (SGS) agro-ecological zones (AEZ). On yam heaps, the symptom incidence averaged 55%, 35%, and 6% for galls, dry rot, and for cracks, respectively. Only the incidence of dry rot was significantly different (P

Soil biodiversity is reflected in the composition of its nematode fauna. In Greenresilient, we are analyzing nematode communities (genera, numbers, feeding types), which provides important information about the soil health status.

The project focussed on the optimization of monitoring strategies and pest management practices. In particular, the project aimed to optimize monitoring methods using attractant traps, to map the incidence for pine wood nematodes and possible vectors, to evaluate phenology and biology of relevant vectors and their pine wood nematodes relationship and to develop molecular identification tests for Monochamus spp. Participating research institutions included 7 research organisations from 5 countries; in four of these countries, the vectors were known to be present, in one country the PWN was known to be present and in one country no vector nor the nematode was known to be established., Report of the Euphresco funded project 'Focusing on Monochamus spp., insect vectors of Bursaphelenchus xylophilus (MONOCHAMUS)'

Various countries keep important nematode populations in (reference) collections for the purpose of research and identification. As funding has been scarce on projects concerning fundamental taxonomic research or the maintenance and accessibility of collections and archives, relevant collections cannot be managed optimally and maintained (i.e. indexing, updating) properly (see Euphresco Strategic Research Agenda). The main aim of this project was to gather together experts of nematode collections in different countries with the objective to make an inventory of live nematode collections in the participating countries: a list of the quarantine nematode populations hosted in the various countries was produced. Another objective was to exchange information on how nematodes are reared (maintenance and storage) in the different collections. Due to current legislation, in particular the Nagoya protocol and the new EU Plant Health Regulation, exchange of (reference) material is hampered severely: this has an impact on research collaboration and on the sustainability of reference collections. This point needs attention., Report of the Euphresco funded project 2016-F-186 'Inventory of living collections of cyst and root knot nematodes in Europe and their maintenance techniques (Cyst and Melo Collect)'

info:eu-repo/semantics/published

The yam nematode, Scutellonema bradys, is a major threat to yam (Dioscorea spp.) production across yam-growing regions. In West Africa, this species cohabits with many morphologically similar congeners and, consequently, its accurate diagnosis is essential for control and for monitoring its movement. In the present study, 46 Scutellonema populations collected from yam rhizosphere and yam tubers in different agro-ecological zones in Ghana and Nigeria were characterised by their morphological features and by sequencing of the D2-D3 region of the 28S rDNA gene and the mitochondrial COI genes. Molecular phylogeny, molecular species delimitation and morphology revealed S. bradys, S. cavenessi, S. clathricaudatum and three undescribed species from yam rhizosphere. Only S. bradys was identified from yam tuber tissue, however. For barcoding and identifying Scutellonema spp., the most suitable marker used was the COI gene. Additionally, 99 new Scutellonema sequences were generated using populations obtained also from banana, carrot, maize and tomato, including the first for S. paralabiatum and S. clathricaudatum, enabling the development of a dichotomous key for identification of Scutellonema spp. The implications of these results are discussed.