Using Autofluorescence to Follow the Effect of Abcisic Acid and Leaf Removal on Color Development of ‘Flame Seedless’ Grapes

• Published in: Acta horticulturae no. 1091; pp. 183 - 186
• Main Authors: Lichter, A, Kaplunov, T, Zutahy, Y, Daus, A, Beno, D, Lurie, S, Sarig, P, Stromza, A
• Format: Journal Article
• Language: English
• Published: International Society for Horticultural Science 01-01-2015
• Subjects: abscisic acid; absorbance; anthocyanins; climate; color; decolorization; dose response; ethylene; juices; leaves; ripening; small fruits; table grapes; Vitis vinifera
• ISSN: 0567-7572; 2406-6168
• DOI: 10.17660/ActaHortic.2015.1091.22

Color development of table grapes can be compromised in hot climate and enhanced by the plant growth regulators ethylene and abscisic acid (ABA). The effect of ABA on ripening of ‘Flame Seedless’ was studied using auto-fluorescence emission from the berries and compared to anthocyanin content in the juice as measured by optical density. In addition, the effect of light during ripening on color development was studied by leaf removal at verison. ABA was applied at 2 time points and 2 rates. The auto-fluorescence was measured using the portable Multiplex III instrument that measures three emission channels derived from four excitation spectra and calculates the ratios between different signals. The FER_RG auto-fluorescence ratio quantified the dose response to ABA and the correlation R2 values were 0.91 or 0.96 for linear and third order trend lines, respectively. Leaf removal at verison did not improve the color as measured by both methods but it enhanced the FER_RUV ratio which correlates to flavonoid content in grape berries. This study demonstrates the efficiency of non-destructive tools in improving phenotypic analysis of table grapes.