Pflanzenparasitäre Nematoden im Ökologischen Landbau – Probleme und Lösungsansätze (Workshop)

Ziel dieses Workshops ist es, umfassende Informationen zur Bedeutung pflanzenparasitärer Nematoden im Ökologischen Landbau bzw. Bioanbau in der Schweiz und Deutschland vorzustellen, die Ursachen der Problematik und Lösungsansätze aufzuzeigen und zu diskutieren, sowie weiteren Forschungsbedarf zu identifizieren. In diesem Workshop sollen pflanzenparasitäre Nematoden hinsichtlich ihrer Biologie und der durch sie verursachten Symptome kurz vorgestellt werden. Des Weiteren werden die Verbreitung und wirtschaftliche Schäden, Lösungsansätze für den Gemüsebau und den Ackerbau vorgestellt und diskutiert. Dieser Workshop bietet die Möglichkeit den Erfahrungsaustausch zwischen Produzenten, Wissenschaftlern und Beratern zu fördern und Informationen zur Bedeutung pflanzenparasitärer Nematoden im ökologischen Landbau zu vermitteln. Folgende Punkte sollen im Rahmen dieses Workshop behandelt werden: Kulturen bzw. Anbausysteme in denen bevorzugt Schäden durch Nematoden auftreten. Einfluss von Standorteigenschaften wie Bodenart, Humusgehalt und pH-Wert. Gibt es Unterschiede zwischen Ökolandbau und konventionellen Landbau? Möglichkeiten Nematodenschäden im Ökolandbau zu verhindern

Screening of sugar beet pre-breeding populations and breeding lines for resistance to Ditylenchus dipsaci penetration and reproduction

Ditylenchus dipsaci is an economically important plant-parasitic nematode affecting European sugar beets. To date, no sugar beet cultivars carrying resistance against D. dipsaci are available to farmers. To find potentially resistant sugar beet lines restricting reproduction and penetration of D. dipsaci, three consecutive in vivo bioassays were carried out. The first experiment determined the penetration rate of D. dipsaci in 79 breeding lines and 14 pre-breeding populations. Based on these results, D. dipsaci penetration and reproduction resistance of eight genotypes was intensively investigated. It could be demonstrated that none of the genotypes showed resistance towards D. dipsaci. However, a high variation of the penetration rate by D. dipsaci was observed among the genotypes. The breeding line ‘DIT_119’ effectively reduced D. dipsaci penetration (34.4 ± 8.8 nematodes/plant at 22 days post-planting) compared to the susceptible control (109.0 ± 16.9) while ensuring a yield comparable to non-inoculated plants. However, the breeding line ‘DIT_119’ did not reduce D. dipsaci reproduction. The paternal line of the cultivar BERETTA KWS, demonstrating a high tolerance to D. dipsaci crown rot symptoms, did not reduce penetration and reproduction. Thus, no correlation can be established between reduced penetration rates, reproduction, and tolerance to D. dipsaci. This study provides an essential basis for the development of resistant sugar beet cultivars to D. dipsaci. The variations observed among genotypes now need to be confirmed with larger-scale screenings

A time travel through nematology in Germany – From the beginnings to the use of artificial intelligence

Das Nachrichtenblatt für den Deutschen Pflanzenschutzdienst, unser heutiges Journal für Kulturpflanzen, feiert seinen 100. Geburtstag. Seinem Ziel, „den im praktischen Pflanzenschutzdienst Tätigen Belehrung und Informationen (zu) übermitteln“, wie Otto Appel zur Einführung schrieb, ist es bis heute treu geblieben. Dies gilt auch für den Bereich der Nematologie. Die Themen haben sich dabei über die Zeit weiterentwickelt. Standen früher Biologie und Wirtspflanzenspektrum einzelner Arten pflanzenparasitärer Nematoden im Fokus des Interesses, so sind es heute Wirt-Parasit Interaktionen, Resistenz und Toleranz von Kulturpflanzen oder der Einfluss von Klimawandel und Globalisierung auf die Verbreitung und das Schadpotenzial der Nematoden. Der vorliegende Beitrag blickt zurück auf die Themen vor 100 Jahren, stellt am Beispiel laufender Arbeiten am Julius Kühn-Institut aktuelle Forschungsthemen vor und gibt einen Ausblick auf die Themen der Zukunft.The Nachrichtenblatt für den Deutschen Pflanzenschutzdienst, today's Journal of Cultivated Plants, celebrates its 100th birthday. It has remained true to its goal of “providing instruc­tion and information to those involved in the practical plant protection service” to this day as stated in its first issue by Otto Appel. This also applies to the field of nematology. The topics have expanded over time and developed further on an international level. While the main focus was initially on the biology and host plant spectrum of the various nematode species, today it is on host-parasite interactions, resistance and tolerance of cultivated plants and the influence of climate change and globalization on the distribution and harmful effects of nematodes. The present article looks back at the topics 100 years ago, presents current research topics using the example of ongoing work at the Julius Kühn Institute and provides an outlook on the topics of the future

Virulence and pathogenicity of four Ditylenchus dipsaci populations on sugar beet

The stem nematode, Ditylenchus dipsaci, is a severe pest in European sugar beet production. In France, Germany, and Switzerland, D. dipsaci damage in sugar beet varies among specific geographic areas. In this study, the reproduction potential of four geographically distinct D. dipsaci populations was determined using sterile carrot disc cultures. In addition, virulence and pathogenicity were investigated in-vivo using sugar beet. No difference was found in the reproduction potential on carrot discs, as well as penetration rate in sugar beet seedlings. The reproduction rate in sugar beet tissue was significantly affected by the D. dipsaci population used. The population from Seeland (CH) showed the highest number of nematodes per plant at 60 dpi (21,071.8 ± 5340.0), compared to the three other populations contained 3588.6 ± 3858.3, 5136.9 ± 4950.8, and 3579.7 ± 5174.2, respectively. Furthermore, the reproduction rate of D. dipsaci was negatively correlated with fresh biomass of sugar beets at 60 dpi. Based on these results, the D. dipsaci population “Seeland” is suitable for breeding programs to detect resistance in sugar beet. After selecting candidate genotypes/varieties, these should be further evaluated for their field resistance in their targeted growing regions

Assessment of a new qPCR tool for the detection and identification of the root-knot nematode Meloidogyne enterolobii by an international test performance study

WOS: 000366635400008Rapid and reliable tools for detection and identification of plant parasitic nematodes are needed to prevent the introduction and spread of quarantine nematodes. A fast and simple DNA extraction method for target nematodes in nematode suspensions obtained from soil samples and a new quantitative real-time PCR method (qPCR) for the specific detection, identification and potential quantification of M. enterolobii were tested in an inter-laboratory comparison (ring test) to allow for a thorough evaluation of these molecular diagnostic tools. A test performance study involving seven laboratories was conducted to validate the developed protocols and to identify possible difficulties when implemented by diagnostic laboratories or national reference centers. Validation included test performance in terms of accuracy, analytical specificity, analytical sensitivity, repeatability, and reproducibility as defined by European Plant Protection Organization (EPPO) standard PM7/98. All positive and negative results for detection, identification and specificity were consistent between different laboratories despite different equipment used. Accuracy of real-time PCR was 100 % because test results and accepted reference values were in agreement. Analytical sensitivity results also matched between laboratories independent of the equipment used. The smallest amount of target DNA tested, two second-stage juveniles of M. enterolobii in a background of 500 non-target nematodes, was reliably detected by all labs. In addition, the repeatability and reproducibility of test results between laboratories was 100 %, even at the limit of detection. Thus, the inter-laboratory comparison showed the robustness of the developed methods and confirmed the in-house validation data.EUPHRESCO II framework, project "Development and validation of innovative diagnostic tools for detection and identification of the quarantine nematode Meloidogyne enterolobii in support of integrated plant protection strategies in the EU member states"; Swiss Federal Office of Agriculture; Belgian Federal Agency for the Safety of the Food ChainThis research project was performed within the EUPHRESCO II framework, project "Development and validation of innovative diagnostic tools for detection and identification of the quarantine nematode Meloidogyne enterolobii in support of integrated plant protection strategies in the EU member states",, via a non-competitive funding mechanism. We thank all colleagues for sharing nematode populations and the Swiss Federal Office of Agriculture as well as the Belgian Federal Agency for the Safety of the Food Chain for financial support