Abstract Detail

Ecophysiology

Tittmann, Susanne [1], Wohlfahrt, Yvette [1], Stoll, Manfred [1].

Initial physiological response of grapevine (Vitis vinifera L.) in a Free Air Carbon dioxide Enrichment (FACE) experiment .

Within the next 35 years an increase of the atmospheric carbon dioxide (CO₂) concentration of approximately 20% to the current level is predicted by the Intergovernmental Panel on Climate Change (IPCC report, 2013). Grapevines are known as climate sensitive; hence impacts on their phenology, physiological processes and grape compositions can be related to a changing climate. Investigations of eco-physiological processes based on chlorophyll fluorescence and leaf gas exchange measurements of field-grown vines can describe the grapevine response to elevated CO₂ conditions. Therefore a Free Air Carbon Dioxide Enrichment (FACE) facility for special crops was established in the Rheingau Valley (N 49.984 E 7.954, Geisenheim Germany). For viticulture experiments Vitis vinifera L. cultivar Riesling (clone 198-30 Gm) grafted on rootstock SO4 (clone 47 Gm) was planted in six FACE rings (12 m diameter, three ambient and three elevated CO₂) in 2012. Fumigation of CO₂ was applied continuously from sunrise to sunset throughout the year. Here we report results of the first growing season under CO₂ enrichment (2014). Short- and long term changes of the acclimation of photosystem II (PSII) were monitored using a multichannel chlorophyll fluorometer (MONI-PAM, Walz). Leaf gas exchange was measured with an open gas-exchange system (GFS-3000, Walz). Further, non-invasive detection of vigour-based leaf indices such as flavonol, nitrogen and chlorophyll were assessed using an optical sensor (Dualex, FORCE-A, France). First results showed that higher light intensity and temperature (during flowering in June 2014 ) resulted in lower effective photochemical quantum yield of PSII and electron transport rate (ETR) but higher non-photochemical quenching for elevated CO₂ grown Riesling compared to ambient conditions. Further, we found higher net assimilation and reduced transpiration rates during flowering under elevated CO₂ conditions. Parallel to these photochemical responses an increase of flavonol index in leaves was observed for elevated CO₂ treated plants, which indicates a higher stress level since flavonol is known as a scavenger pigment to avoid damages of the photosystem at severe or prolonged stress situation. Altogether we found first evidence for significant responses of Riesling grown under elevated CO₂ conditions. In conclusion, the achieved results may provide first insights of the impact of future conditions on vegetative and generative parameters. Since the preliminary data are only one-season results further investigations will be necessary to confirm our obtained findings.

1 - Geisenheim University, Department of general and organic viticulture, Von-Lade-Str. 01, Geisenheim, Hesse, 65366, Germany

Keywords:
climate change
grapevine
Photosynthesis
Chlorophyll fluorescence.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PEP006
Abstract ID:717
Candidate for Awards:None