Submitted to: Near Infrared Spectroscopy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2009
Publication Date: 9/24/2009
Publication URL: www.ars.usda.gov/SP2UserFiles/Place/54300520/410NIRabsorbancecharacteristicsofDONandofsoundandFusariumDONNIRShantha.pdf
Citation: Peiris, K., Pumphrey, M.O., Dowell, F.E. 2009. NIR absorbance characteristics of deoxynivalenol and of sound and Fusarium-damaged wheat kernels. Journal of Near Infrared Spectroscopy. 17:213-221. doi: 10.1255/jnirs.846. Interpretive Summary: Fusarium head blight is a fungus that causes yield losses in wheat and barley, produces the mycotoxin deoxynivalenol, and affects end-use functionality. Detecting the fungus or toxin in single kernels will help breeders rapidly and objectively evaluate lines for resistance. Also, sorting kernels based on the presence of the fungus or level of toxin may help breeders select for resistance to the fungus or toxin within lines. We measured near-infrared absorption spectra of pure deoxynivalenol, and kernels with and without the toxin or fungus. Specific peaks in the pure toxin were related to those seen in infected kernels. Other differences in infected and uninfected kernels were attributed to changes in the levels of grain food reserves related to the invasion of the fungus. This information will be used to improve near-infrared calibrations used to sort single kernels based on Fusarium infection or DON levels. This work was partially funded by the US Wheat and Barley Scab Initiative and supports work by breeders to develop lines resistant to Fusarium head blight.
Technical Abstract: The near infrared (NIR) absorption spectra of deoxynivalenol (DON) and single wheat kernels with or without DON were examined. The NIR absorption spectra of 0.5-2000 ppm of DON in acetonitrile were recorded in the 350-2500 nm range. Second derivative processing of the NIR spectra and spectral subtractions showed DON absorption bands at 1408, 1904 and 1919 nm. NIR spectra of sound and Fusarium-damaged scabby kernels were also acquired using two instruments. Subtraction of average absorption spectra and second derivative spectra were evaluated to identify different NIR signatures of the two types of kernels. Differences in peak heights and positions of the NIR absorption bands of the kernels were noted. At 1204, 1365 and 1700 nm, the differences were in the heights of the absorption peaks. Such differences may be attributed to changes in the levels of grain food reserves and other structural compounds. Shifts in absorption peak positions between the two types of kernels were observed at 1425-1440 nm and 1915-1930 nm. These differences may arise from other NIR active compounds, such as DON, which are not common for the two types of grains. Since the NIR absorption of DON may have contributed to the shifts between sound and Fusarium-damaged kernels, this study indicates the potential for NIR spectrometry to evaluate Fusarium damage in single kernels based on the DON levels.