Assessment of Fusarium Infection and Mycotoxin Contamination of Wheat Kernels and Flour Using Hyperspectral Imaging

Abstract

Fusarium head blight (FHB) epidemics in wheat and contamination with Fusarium mycotoxins has become an increasing problem over the last decades. This prompted the need for non-invasive and non-destructive techniques to screen cereal grains for Fusarium infection, which is usually accompanied by mycotoxin contamination. This study tested the potential of hyperspectral imaging to monitor the infection of wheat kernels and flour with three Fusarium species. Kernels of two wheat varieties inoculated at anthesis with F. graminearum, F. culmorum, and F. poae were investigated. Hyperspectral images of kernels and flour were taken in the visible-near infrared (VIS-NIR) (400–1000 nm) and short-wave infrared (SWIR) (1000–2500 nm) ranges. The fungal DNA and mycotoxin contents were quantified. Spectral reflectance of Fusarium-damaged kernels (FDK) was significantly higher than non-inoculated ones. In contrast, spectral reflectance of flour from non-inoculated kernels was higher than that of FDK in the VIS and lower in the NIR and SWIR ranges. Spectral reflectance of kernels was positively correlated with fungal DNA and deoxynivalenol (DON) contents. In the case of the flour, this correlation exceeded r = −0.80 in the VIS range. Remarkable peaks of correlation appeared at 1193, 1231, 1446 to 1465, and 1742 to 2500 nm in the SWIR range.

Fusarium Head Blight: Effect of Infection Timing on Spread of Fusarium graminearum and Spatial Distribution of Deoxynivalenol within Wheat Spikes

“…This can also be achieved by incubating the plants under plastic bags for 48 h after inoculation. Alisaac et al [24] showed that incubating wheat plants under plastic bags for 48 h after inoculation resulted in high fungal DNA content and DON contamination even with a concentration of 1 × 10 4 conidia/mL of inoculum. The current study demonstrated the ability of F. gra-minearum to infect and contaminate wheat kernels with DON up to 25 daa.…”

“…The experimental unit consisting of two plants per pot was grown in plastic pots of 12 × 12 × 20 cm in size. The greenhouse conditions were: 16/8 h (day/night) photoperiod obtained from an artificial light with a light intensity of >300 µmol m −2 s −1 (Philips SGR 140, Hamburg, Germany); 20 ± 2 • C temperature, 50-70% relative humidity (RH), and water on demand [24].…”

“…The isolate S.19 of Fusarium graminearum was used from the collection of the Institute of Crop Science and Resource Conservation (INRES), University of Bonn. This isolate was used in previous studies and proved its virulence and ability to produce high amounts of mycotoxins [24]. Fungus culturing and inoculum production were performed according to Alisaac et al [25].…”

From visual estimates to fully automated sensor-based measurements of plant disease severity: status and challenges for improving accuracy

“…Huang et al (2007) demonstrated reliable measurement of severity using a 9-class ordinal scale for severity of yellow rust in wheat (R 2 = 0.91). Other studies have explored classification accuracy using ordinal groupings in classes of visually assessed specimens as the assumed gold standard (Bravo et al 2003;Alisaac et al 2018;Thomas et al 2018a;Alisaac et al 2019), including the use of confusion matrices. Regression analysis of visual estimates of diseased wheat spikes on a percentage scale and hyperspectral measurements also had demonstrable reliability (R 2 up to 0.828, Kobayashi et al 2016).…”

A Comparative Study on Deoxynivalenol Mycotoxin Level in Wheat Flour and Bread Samples

“…he Deoxynivalenol (DON) mycotoxin is generally produced by Fusarium graminearum and Fusarium culmorum [1,2]. This toxin is commonly found in cereal products [3][4][5].…”