Exploring the influence of rapeseed cultivar and pathogen isolate on Acremonium alternatum's efficacy in clubroot disease control

• Published in: European journal of plant pathology Vol. 170; no. 3; pp. 519 - 534
• Main Authors: Auer, Susann, Zamani-Noor, Nazanin, Mahfoud, Yamen, Ludwig-Müller, Jutta
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-11-2024; Springer Nature B.V
• Subjects: Abiotic factors; Acremonium; Agricultural practices; Agriculture; Biological control; Biological treatment; Biomedical and Life Sciences; Brassica napus; Clubroot; Control methods; Cultivars; Disease; Disease control; Ecology; Effectiveness; Growing season; Inoculum; Integrated pest management; Life Sciences; Medical treatment; Pest control; Pest resistance; Plant diseases; Plant Pathology; Plant Sciences; Plasmodiophora brassicae; Rapeseed; Signs and symptoms; Soil resistance; Spores; Integrated pest management (IPM); Biological control; Endophytic fungus
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1007/s10658-024-02916-y

Clubroot disease, caused by
Plasmodiophora brassicae
, ranks among the most significant diseases affecting rapeseed cultivars, leading to substantial annual yield losses. Current control methods are limited to a small selection of chemical or biological treatments. Using biocontrol organisms presents a promising strategy for reducing disease severity and promoting plant vigour. However, their efficacy is strongly dependent on biotic and abiotic factors during the growing season, as well as the specific application conditions. In the present study, we evaluated the efficacy of the biocontrol fungus
Acremonium alternatum
in reducing clubroot disease symptoms across different susceptible and resistant rapeseed cultivars (
Brassica napus
) under various experimental greenhouse settings employing different types of
P. brassicae
inoculum: a uniform single spore isolate e3 and two German field isolates P1 and P1 ( +). We found that
A. alternatum
can reduce clubroot disease symptoms in susceptible rapeseed cultivars Visby, Ability and Jenifer, but not cv. Jumbo, when inoculated with the aggressive single spore isolate
P. brassicae
e3 at moderate (10
6
 spores mL
−1
) and high (10
7
spores mL
−1
) densities.
A. alternatum
enhanced plant vitality and shoot biomass in cv. Visby inoculated with field isolates P1 or P1 ( +) but did not considerably reduce clubroot severity there. The clubroot-resistant cv. Mentor displayed a reduction in clubroot symptoms after
A.

alternatum
treatment. In conclusion,
A. alternatum
holds some promise in managing moderate
P.

brassicae
levels in the soil and could serve as an option in integrated pest management of clubroot disease when combined with resistant cultivars.