dr. A (Arne) Schwelm

dr. A (Arne) Schwelm

Post Doc

Research conducted by the Laboratory of Nematology is part of the research prgram of the Graduate School Experimental Plant Sciences (EPS) and the C.T. de Wit Graduate School for Production Ecology & Resource Conservation (PE&RC)


Plasmodiophorids (Phytomyxea, Rhizaria) are soil dwelling plant-parasitic protist that rely on host plants to multiply. The best-known species of this group is the clubroot pathogen Plasmodiophora brassicae, that causes tumorous root growth on host plants. Clubroot is a major threat of cruciferous crops worldwide. Control options of this soil-borne disease are limited due to the long persistence of the P. brassicae resting spores in the soil, limited sources of plant resistance genes and lack of chemical control agents.


However, plants recruit specific rhizosphere microbiomes from the bulk soil. The rhizosphere microbiome has an important function for plant health and has the potential to control soil-borne diseases. An infection with P. brassicae heavily alters the metabolism of the plant roots in the clubroots and will certainly impact the composition of the soil microbiome.


Using a holistic approach bacterial, fungal, nematode and protistan communities will be simultaneously characterize from the microbiome of bulk and rhizosphere soils associated with roots of healthy and clubroot-infected plants in samples across Europe. I aim to correlate the microbiome structure and keystone taxa to the pathogen existence and plant infection and abiotic factors. In this context, temporal dynamic changes in the microbiome should reveal trophic interactions between the host plant, P. brassicae and the soil microbiome. Thereby potential disease enhancing organisms, antagonists and biocontrol agents against this notorious pathogen can be identified. The gained information will be used to manipulate soil parameters and its microbiome in greenhouse experiments and field trials, aiming to construct disease suppressive soils. This is new approach of clubroot research that leads towards new sustainable disease biocontrol possibilities that could be extendable to the disease-management of other soil-borne plant pathogens.