The Application of Terahertz Time-Domain Spectroscopy to Identification of Potato Late Blight and Fusariosis

Abstract

Fusarium and late blight (fungal diseases of cereals and potatoes) are among the main causes of crop loss worldwide. A key element of success in the fight against phytopathogens is the timely identification of infected plants and seeds. That is why the development of new methods for identifying phytopathogens is a priority for agriculture. The terahertz time-domain spectroscopy (THz-TDS) is a promising method for assessing the quality of materials. For the first time, we used THz-TDS for assessing the infection of seeds of cereals (oats, wheat and barley) with fusarium and potato tubers of different varieties (Nadezhda and Meteor) with late blight. We evaluated the refractive index, absorption coefficient and complex dielectric permittivity in healthy and infected plants. The presence of phytopathogens on seeds was confirmed by microscopy and PCR. It is shown, that Late blight significantly affected all the studied spectral characteristics. The nature of the changes depended on the variety of the analyzed plants and the localization of the analyzed tissue relative to the focus of infection. Fusarium also significantly affected all the studied spectral characteristics. It was found that THz-TDS method allows you to clearly establish the presence or absence of a phytopathogens, in the case of late blight, to assess the degree and depth of damage to plant tissues.

Raman Spectroscopy Enables Non-Invasive Identification of Mycotoxins p. Fusarium of Winter Wheat Seeds

“…Real-time PCR. Primer specific for these pathogen was used to identify Fusarium graminearum in the respective samples (F-5 -GTTGATGGGTAAAAGTGTG-3 ; R-5 -CTCTCA TATACCCTCCG-3 , Intergenic Spacer of rDNA (IGS region)) [12]. Primer was synthesized at the QuantStudio TM 5 Real-Time PCR System (Thermo Fisher, Waltham, MA, USA).…”

Plant Disease Detection Technology Assessment

“…LWIR imaging and terahertz spectroscopy are often used to assess water movement in plants, through root uptake and leaf transpiration through stomata. Diseases caused by fungi and oomycetes can interfere with transpiration, enabling plant disease diagnosis by thermal infrared imaging [180] as well as terahertz time-domain spectroscopy [181]. Thermal imaging has also been used to detect pests in stored grains due to animal respiration [182] and damage to guava fruit caused by disease [183].…”

Optical Methods for the Detection of Plant Pathogens and Diseases (Review)

“…It has been shown that the THz-TDS method makes it possible to assess the degree of Fusarium infection in cereal seeds (oats, wheat and barley) and late blight in potato tubers. Changes are observed in refractive indices, absorption coefficients and dielectric functions in healthy and infected plants [155]. Terahertz imaging has also been used to identify fungal infections in chestnut trees [156], powdery mildew in tomato leaves [157] and wheat mold [158].…”