Host-range and genetic diversity in stem nematodes

Stem nematodes are a major agricultural pest, however we lack a good understanding of their host-range and outbreaks. By using state-of-the-art genetic tools we hope to better understand this species.


Stem nematodes of the species Ditylenchus dipsaci have been thoroughly studied over the past 70 years, yet these studies have not been able to understand the host-range of this species well enough. Although there is some understanding, the early work has mainly led to dividing stem nematodes in many different groups (‘pathotypes’). However, it is clear that these pathotypes are not predictive enough for targeted control measures. Furthermore, it is even the question if there is any genetic basis for the assigned pathotypes. Such an understanding is required to make useful predictions for agricultural practice.

Project description

We will establish a collection of Ditylenchus dipsaci from various infections in the field, ranging from bulbous plants, such as tulips, daffodils, hyacinths and onions, but also maize, potatoes, carrots, sugar beets, legumes and various green fertilizer crops. These we will characterize genetically by whole-genome short-read sequencing. For genetically representative populations, reference genomes will be constructed using long-read sequencing technologies. Ultimately, the aim of this project is the molecular unraveling of the host plant status of the stem nematode races in the Netherlands, which makes it possible to: i) draw up sustainable crop-rotations, ii) provide field-specific cultivation advice based on a rapid diagnostic test, iii) timely phytosanitary measures, and iv) perform targeted and efficient testing and breeding for resistant host plants, including green fertilizers.