Autofluorescence of grape berries following Botrytis cinerea infection
Abstract:Grey mould is caused by Botrytis cinerea, a fungus infecting over 200 plant species worldwide and causing tremendous harvest losses in vineyards. We evaluated the potential of plant fluorescence to achieve early detection of B. cinerea in grapevine (Vitis vinifera L.) berries. By comparing control and artificially inoculated berries, six images of fluorescence were taken at four wavelengths under 360 nm excitation (F 440/F360 (fluorescence emitted at 440 nm under a 360 nm excitation), F 520/F360, F 690/F360 and F 790/F360) and at two wavelengths under 436 nm excitation (F 690/F436 and F 790/F436). Data treatments include proper image correction, interest area selection, fluorescence ratios computation and edge detection. In the early stages, before 3 DAI (days after inoculation), the discrimination between wounded and symptomatic berries could not easily be achieved using blue fluorescence solely (440 nm). However, using blue out of far-red fluorescence ratio (F 440/F 740), it was possible to detect infected berries starting as early as 4 DAI. Using image analysis and edge detection over UV-epidermal transmittance measured at 690 nm, it was possible to detect botrytized berries as early as 3 DAI.
Document Type: Research Article
Affiliations: 1: Unité Mixte de Recherche Information et Technologies pour les Agroprocédés (UMR-ITAP), Cemagref, 361, rue Jean-François Breton, BP 5095, Montpellier34 196Cedex 5, France 2: Unité Mixte de Recherche (UMR) Santé Végétale, Institut National de Recherche Agronomique (INRA), Institut des Sciences de la Vigne et du Vin (ISVV), 71, Avenue Edouard Boaux, BP81, Villenave d'Ornon33883Cedex, France
Publication date: July 20, 2011