European Journal of Plant Pathology

, Volume 152, Issue 3, pp 677–689 | Cite as

Pathogenicity and toxigenicity of Fusarium verticillioides isolates collected from maize roots, stems and ears in South Africa

  • A. Schoeman
  • B. C. Flett
  • B. Janse van RensburgEmail author
  • E. Ncube
  • A. Viljoen


Fusarium verticillioides is most frequently associated with maize in South Africa. It colonises maize roots, stems and ears endophytically and causes diseases such as Fusarium ear rot (FER) and stalk rot. Fusarium verticillioides can produce fumonisins, which are toxic secondary metabolites harmful to humans and animals. It is, however, unknown whether endophytic and pathogenic isolates from distinct maize tissues differ in their ability to cause disease and produce fumonisins. In this study, Fusarium spp. were collected from maize roots, stems and kernels for phylogenetic analysis and the F. verticillioides isolates were subjected to pathogenic and toxigenic comparison. The translation elongation 1-α (TEF1) gene of the isolates was sequenced, and a phylogenetic tree constructed with maximum likelihood (ML) and Bayesian interference (BI) inferred. Fumonisin production of F. verticillioides isolates was determined in vitro and in planta by using high performance liquid chromatography, and virulence of the isolates was determined by silk channel inoculation of maize ears under field conditions. F. verticillioides was the species with the highest number of isolates followed by F. temperatum and then F. subglutinans. Phylogenetic analyses clustered the different Fusarium spp. according to species. Fumonisin production by F. verticillioides isolates varied from 0 to 21.3 mg/kg in vitro, and 0–16.2 mg/kg in planta. All the F. verticillioides isolates produced FER symptoms, including isolates from roots and stems. Fusarium verticillioides isolates in South Africa thus presented a species highly diverse in toxigenicity, but not in virulence. This finding has implications for managing mycotoxins in maize, as visible symptoms might be misleading to the actual toxin level present, for example low level of disease severity might represent high fumonisin levels and vice versa. The high numbers of F. temperatum, also a mycotoxin producer highlights the concern that kernels could be contaminated with more than one mycotoxin. Integrated disease management of not only F. verticillioides but all Fusarium spp. should thus focus strongly on reducing fungal contamination of maize and the detoxification of grain with focus on using regionally adapted maize varieties.


Fumonisins Fusarium verticillioides Pathogenicity Phylogeny Toxigenicity 



The authors wish to thank the Agricultural Research Council – Grain Crops Institute (South Africa) for the use of infrastructure and funding. The National Research Foundation and Maize Trust is also acknowledged for funding.


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Copyright information

© Koninklijke Nederlandse Planteziektenkundige Vereniging 2018

Authors and Affiliations

  • A. Schoeman
    • 1
    • 2
  • B. C. Flett
    • 1
  • B. Janse van Rensburg
    • 1
    Email author
  • E. Ncube
    • 1
  • A. Viljoen
    • 2
  1. 1.Agricultural Research Council-Grain Crop InstitutePotchefstroomSouth Africa
  2. 2.Department of Plant PathologyStellenbosch UniversityMatielandSouth Africa

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