Influence of biotic and abiotic stress on physiological traits and water use efficiency in grapevine

Abstract

According to the latest forecasts of climate change, water will become scarcer in the near future, especially in Mediterranean areas. Increasing water scarcity would force viticulture to make changes in the use of cultivars and/or making irrigation necessary practice. Improving vineyard water use efficiency (WUE) is therefore crucial for a sustainable viticulture industry in Mediterranean regions. On the other hand, the presence of Grapevine leaf-roll-associated virus-3 (GLRaV-3) provokes sommee of the most important diseases affecting grapevines. In this sense, the optimization of water use for vineyards in a real context of virus infection is a core subject of interest to sustainability in viticulture. In the present work, we focused on determining the interaction of biotic (GLRaV-3) and abiotic (drought) stresses on grapevine growth, WUE at leaf level, at whole plant level and long term WUE (based on d¹³C) in two grapevine cultivars (Malvasia de Banyalbufar and Giro-Ros). Virus-free and GLRaV-3 infected potted plants were compared under water deficit (WD) and well-watered (WW) conditions. Growth parameters were reduced in both varieties under WD. The virus decreased growth, being more affected Malvasia cv. than Giró-Ros cv. As expected, water stress increased WUE in both varieties. In Giró-Ros cv. the infection supposed higher WUEwp under WD. These results were confirmed by leaf d¹³C values. In conclusion, this study shows how the virus infection has no significant effects on growth parameters, but can affect water use and hence WUE. Differences between cultivars can be attributed to the genetic variability in plant-pathogen interactions but viral quantity differences between cultivars cannot be discarded