Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 11, 2009
Publication Date: July 1, 2009
Citation: Calderon, F.J., Hanson, L.E., Panella, L.W., Reeves III, J.B., Vigil, M.F. 2009. Mid-Infrared and Near-Infrared Spectroscopic Properties of Fusarium Isolates: Effects of Culture Conditions. Meeting proceedings poster presentation at the American Phytopathological Society Annual Meeting. Aug. 1-5, 2009. Portland, OR. Interpretive Summary: This paper reports on findings that Fusarium fungi, known to cause crown rot and seed blight, can be distinguished from other fungi by infrared spectroscopy. We show that the ability of this possible new technology to differentiate the fungi depends on the culture conditions of the isolates before they are analyzed with the spectrometer
Technical Abstract: The Fusarium genus includes soil saprobes as well as pathogenic or toxin-producing species. Traditional classification of Fusarium isolates is slow and requires a high level of expertise. The objective of this project is to describe culture condition effects on mid-infrared (MidIR) and near-infrared (NIR) absorbance spectra of several Fusarium species. The ultimate goal of this research is finding diagnostic spectral regions that can be used to quickly differentiate fusaria. We cultured isolates from sections Roseum (F. graminearum, F. avenaceum) and Gibbosums (F. equiseti, F. acuminatum). F. solani was included as an outgroup from the Nectria clade, along with two non-Fusarium (Phoma and Bipolaris). The isolates were grown on two different growth media (potato dextrose broth or V8 broth), under light or dark conditions, and at different temperatures (20 °C or 25 °C). Principal components analysis of the MidIR spectra shows a strong growth medium influence. The V8 medium separated fusaria from the outgroups better than the PDA. Light and temperature conditions had little effect on the MidIR spectral properties. The multivariate analysis of the NIR separated the fusaria from the Bipolaris and Phoma isolates, and also showed a strong growth medium effect. This results show the possible diagnostic value of infrared spectroscopy to differentiate fusaria from other fungal species, as well as the possible effect of nutritional state on the separation of the taxa.