Fusarium meridionale and F. graminearum both cause Gibberella ear rot (GER) and Gibberella stalk rot (GSR) of maize in Brazil, but the former is much more common. Recent work with two isolates of each from maize suggested this dominance could be caused by greater aggressiveness and competitiveness of F. meridionale on maize. We evaluated pathogenicity and toxigenicity of 16 isolates of F. graminearum and 24 isolates of F. meridionale recovered from both wheat and maize. Strains were individually inoculated into ears of four maize hybrids in field trials. GER severity varied significantly between isolates within each species. Although ranges overlapped, the average GER severity induced by F. meridionale (25.2%) was two times as high overall as that induced by F. graminearum (12.8%) for isolates obtained from maize but was similar for those isolated from wheat (19.9 and 21.4%, respectively). In contrast, severity of GSR was slightly higher for F. graminearum (22.2%) than for F. meridionale (19.8%), with no effect of the host of origin. Deoxynivalenol and its acetylated form 15ADON were the main mycotoxins produced by F. graminearum (7/16 strains), and nivalenol toxin was produced by F. meridionale (17/24 strains). Six isolates of F. graminearum and three of F. meridionale also produced zearalenone. Results confirmed that F. meridionale from maize is, on average, more aggressive on maize but also suggested greater complexity related to diversity among the isolates within each species and their interactions with different hybrids. Further studies involving other components of the disease cycle are needed to more fully explain observed patterns of host dominance.
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|Published - Feb 2022
Bibliographical noteFunding Information:
†Corresponding authors: E. M. Del Ponte; email@example.com, and L. J. Vaillancourt; firstname.lastname@example.org Funding: This work was partially supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, Multistate Project number 1008664, the National Institute of Food and Agriculture Hatch Program under 1014371, and Fundac¸ão de Amparo à Pesquisa do Estado de Minas Gerais. We thank the Conselho Nacional de Desenvolvimento Científico e Tecnológico for providing a graduate scholarship to F. J. Machado and research scholarship to E. M. Del Ponte, and Coordenac¸ão de Aperfeic¸oamento de Pessoal de Nível Superior for providing a sandwich fellowship to F. J. Machado.
This work was partially supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, Multistate Project number 1008664, the National Institute of Food and Agriculture Hatch Program under 1014371, and Funda??o de Amparo a Pesquisa do Estado de Minas Gerais. We thank the Conselho Nacional de Desenvolvimento Cient?fico e Tecnologico for providing a graduate scholarship to F. J. Machado and research scholarship to E. M. Del Ponte, and Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior for providing a sandwich fellowship to F. J. Machado.
© 2022 The American Phytopathological Society
- Fungal pathogens
- Postharvest pathology
ASJC Scopus subject areas
- Agronomy and Crop Science
- Plant Science