The microbiome associated with Trichodorus primitivus, a virus vector nematode, is enriched with Proteobacteria compared to soil
Although soil biota mediates many key processes that deliver multiple environmental benefits, interactions between soil biota are generally not well characterised. To date, studies on the associations between nematodes and bacteria have mostly focussed on either intracellular bacteria that have potential roles in, for example, nutritional supplementation or contribute to crop pathogenesis by endoparasitic nematode species, i.e., those species that have a component of their life cycle within the plant host. In this study we characterise the bacterial communities associated with an ectoparasitic nematode species, Trichodorus primitivus, whose complete life cycle is external to the plant host and feeds through a hollow tube which punctures root cells prior to ingestion of cell contents. Compared to the soil from which the nematodes were extracted, the diversity of bacterial communities associated with T. primitivus was reduced, driven by a significant enrichment of Proteobacteria and was consistent across all sampled fields. Dominance of Proteobacteria associated with endoparasitic nematode species has previously been reported with suggested potential roles in crop pathogenesis. Although represented by only a few amplicon sequence variants, Xiphinematobacter, a known intracellular bacteria associated with Xiphinema americanum-group nematodes was detected, with a relative abundance greater in soil than T. primitivus. The study advances knowledge on the interactions between bacteria and ectoparasitic nematodes which could underpin novel strategies for nematode control to deliver sustainable agronomic practice in crop production.