spectral remote sensing measurements for detection of viral infections in tobacco plants (nicotiana tabacum l.) | 量子荧光|微型光纤光谱仪-ag贵宾会

the ability to identify diseases in an early infection stage and to accurately quantify the severity of infection is crucial in plant disease assessment and management. a greenhouse study was conducted to assess changes in the leaf spectral reflectance and fluorescence of young tobacco plants during viral infections with the aim to evaluate the remote sensing spectral measurements as a tool for early identification and discrimination of different diseases. at the growth stage of 2-4 expanded leaf, the plants were inoculated with tobacco sap from leaves with clearly manifested infection symptoms of the four most widely spread in bulgaria viruses: cucumber mosaic virus - cmv, tomato spotted wilt virus - tswv, tomato mosaic virus - tomv and potato virus y - pvy. the leaf reflectance and fluorescence spectra were collected on the 7th day after inoculation using an ocean optics usb2000 spectrometer in the spectral ranges 450-850 nm and 600-850 nm, respectively. specific differences in reflectance spectra between virus-infected and uninfected tobacco leaves were observed in four wavelength intervals: green (520-580 nm), red (640-680 nm), red edge (690-710 nm) and near infrared (720- 760 nm). results of statistical analysis by applying student’s t-criterion showed statistically significant differences against reflectance data of uninfected leaves at least in three of the investigated spectral ranges in dependence on the virus specificity. the fluorescence spectra of all infected leaves differed statistically significant in the spectral range 640-680 nm. the results of spectral analysis qualify the two remote sensing techniques as a promising tool for cost-effective, non-destructive method for early detection of viral infections.