FTIR spectra of grapevines (Vitis vinifera L.) in the presence of virus infections

A nondestructive, efficient and accurate fingerprinting method using Fourier Transform Infrared spectroscopy is proposed for diagnosing virus infection in grapevine plants. This analysis explores the vibration of functional groups present in macromolecules and shows the molecular structural changes through shifts in wavenumber. Three viruses were used on six grapevine cultivars: Grapevine fleck virus - infected 'Moldova' and 'Grasă de Cotnari', Grapevine fanleaf virus - infected 'Fetească neagră 7 Od.' and 'Italia', Grapevine leafroll associated virus type 1+3 - infected 'Cabernet Sauvignon' and 'Bicane'. Symptom-free leaves from healthy and virus infected grapevines were used. The virus infected grapevine plants revealed signs of change in the FTIR spectra. The presence of virus-induced disease in grapevine plants showed a distinctive spectrum in carbohydrates (1185-1000 cm^-1) that could be used to distinguish an infected plant from a healthy one. Leafroll associated virus type 1+3 induced the most evident spectrum changes in infected plants.