SUSANN AUER and JUTTA LUDWIG-MÜLLER
Technische Universität Dresden, Institute für Botanik, 01062 Dresden, Germany
*Corresponding author, E-mail: Jutta.Ludwig-Mueller@tu-dresden.de
The clubroot pathogen Plasmodiophora brassicae infects economically important Brassica crops such as oilseed rape and vegetable brassicas. Clubroot results in abnormally growing roots and restricts the flow of water and nutrients to the upper plant parts, thereby inducing wilting. Yield loss affects about half the percentage of infected plants. Due to its complex and well-adapted life cycle the pathogen is difficult to control by chemical and cultural means and therefore continues to spread around the globe. Infested fields can no longer be used effectively for cultivation of crop plants for at least the next ten years. Despite costly breeding of resistant cultivars, recent research leans towards alternative, low-impact and environmentally friendly methods to control clubroot. To this end we have previously identified the endophyte Acremonium alternatum, a known biological control agent in several countries, to show promising antagonistic effects in clubroot-infected A. thaliana and Chinese cabbage (Brassica rapa). Here, we will describe its effect on the growth, development and clubroot control of oilseed rape (Brassica napus). While the clubroot symptoms were not clearly reduced after co-inoculation with A. alternatum and P. brassicae on oilseed rape roots, the aboveground plant parts were delayed in senescence and produced more seeds, which is indicative of an increase in yield after A. alternatum treatment. The long-term goal of this work is to contribute to a fundamental understanding of endophyte-plant interactions and an effective reduction of clubroot to be used in integrated pest management for oilseed rape and other cabbage varieties.
Keywords: Acremonium alternatum; Brassica napus; clubroot disease; endophytic fungus; Plasmodiophora brassicae; seed yield.