Biocontrol agent Fusarium oxysporum f.sp. strigae has no adverse effect on indigenous total fungal communities and specific AMF taxa in contrasting maize rhizospheres

Judith Zimmermann; Mary K Musyoki; Georg Cadisch; Frank Rasche

doi:10.1016/j.funeco.2016.05.007

Biocontrol agent Fusarium oxysporum f.sp. strigae has no adverse effect on indigenous total fungal communities and specific AMF taxa in contrasting maize rhizospheres

Fungal Ecol. 2016 Oct:23:1-10. doi: 10.1016/j.funeco.2016.05.007.

Authors

Judith Zimmermann¹, Mary K Musyoki¹, Georg Cadisch¹, Frank Rasche¹

Affiliation

¹ Institute of Agricultural Sciences in the Tropics (Hans-Ruthenberg-Institute), University of Hohenheim, Stuttgart, Germany.

Abstract

We studied the effects of Fusarium oxysporum f.sp. strigae (Fos), a soil-borne biocontrol agent (BCA) against Striga hermonthica, on total fungal and arbuscular mycorrhizal fungal (AMF) taxa in rhizospheres of maize in both clayey and sandy soil. Effects of Fos-BCA 'Foxy-2' were evaluated against (1) S. hermonthica presence, and (2) organic fertilization with Tithonia diversifolia residues at 14, 28 and 42 d after 'Foxy-2' inoculation, via DNA-based quantitative PCR and TRFLP fingerprinting. In both soils, 'Foxy-2' occasionally promoted total fungal abundance, while the community composition was mainly altered by T. diversifolia and S. hermonthica. Notably, 'Foxy-2' stimulated AMF Gigaspora margarita abundance, while G. margarita was suppressed by S. hermonthica. Total fungal and AMF abundance were promoted by T. diversifolia residues. In conclusion, 'Foxy-2' resulted in no adverse effects on indigenous rhizosphere fungal communities substantiating its environmental safety as BCA against S. hermonthica.

Keywords: Arbuscular mycorrhizal fungi; Biological control agent; Environmental safety; Fusarium oxysporum f.sp. strigae; Non-target rhizosphere fungi; Striga hermonthica.