Giesco
EFFECTS OF UV-B, WATER DEFICIT, NATURAL PLANT REGULATOR SPRAYS AND ITS INTERACTIONS ON LEAVES, GRAPES, AND WINES OF CV. MALBEC EFECTOS DE UV-B, RESTRICCIÓN HÍDRICA, APLICACIONES DE FITOREGULADOR NATURAL Y DE SUS INTERACCIONES SOBRE HOJAS, BAYAS Y VINOS DEL CV. MALBEC
ALONSO, Rodrigo1, 2*; BERLI, Federico1; FONTANA, Ariel1; BUSCEMA, Fernando2; PICCOLI, Patricia1; BOTTINI, Rubén1. 1 Instituto de Biología Agrícola de Mendoza (IBAM), Facultad de Ciencias Agrarias, UNCuyo - CONICET, Mendoza, Argentina. 2 Catena Institute of Wine (CIW) - Mendoza. Argentina. *Corresponding author: ralonso@catenainstitute.com
Abstract: Malbec is the most important grape variety cultivated in Argentina. In Mendoza, at 1450 m asl, the intensity of natural ultraviolet-B (UV-B) radiation is high and causes a significant increase on polyphenol content in berries. Water deficit is a cultural practice known for increasing grape phenolic content in berries as well. Stressing conditions and/or environmental signals, including water deficit and UV-B, cause an increase of the natural plant regulator abscisic acid (ABA). The aim of the present work was to study the effect of UV-B, water deficit, ABA sprays, and their interactions, on high altitude Malbec vines, grapes and wines. Morphological, physiological and biochemical parameters were evaluated during three seasons. The results show that UV-B, given independently, increased low molecular weight polyphenols (LMWP) in grape skins and wines. Water deficit alone did not modify the LMWP or anthocyanin profile of grape skins and wine. ABA sprays increased terpenes in leaves and LMWP and anthocyanins in berries. Finally, the results indicate that ABA sprays or water deficit cannot replace the effect of natural UV-B light.
Keywords: ultraviolet-B, abscisic acid, Malbec, water deficit, polyphenols
Abstract: Malbec is the most important grape variety cultivated in Argentina. In Mendoza, at 1450 m asl, the intensity of natural ultraviolet-B (UV-B) radiation is high and causes a significant increase on polyphenol content in berries. Water deficit is a cultural practice known for increasing grape phenolic content in berries as well. Stressing conditions and/or environmental signals, including water deficit and UV-B, cause an increase of the natural plant regulator abscisic acid (ABA). The aim of the present work was to study the effect of UV-B, water deficit, ABA sprays, and their interactions, on high altitude Malbec vines, grapes and wines. Morphological, physiological and biochemical parameters were evaluated during three seasons. The results show that UV-B, given independently, increased low molecular weight polyphenols (LMWP) in grape skins and wines. Water deficit alone did not modify the LMWP or anthocyanin profile of grape skins and wine. ABA sprays increased terpenes in leaves and LMWP and anthocyanins in berries. Finally, the results indicate that ABA sprays or water deficit cannot replace the effect of natural UV-B light.
Keywords: ultraviolet-B, abscisic acid, Malbec, water deficit, polyphenols