|Author:||Medrano, H. ; Escalona, J. M. ; Cifre, J. ; Bota, J. ; Flexas, J.|
|Book Group Author:||NA|
The effects of moderate irrigation, compared with non-irrigation, on leaf photosynthesis and transpiration, grape yield, and quality parameters, were studied over ten years (from 1992 to 2001) in two cultivars (Tempranillo and Manto Negro) of grapevines (Vitis vinifera) grown in the field (Spain) to determine the relationships between water availability, canopy water losses, photosynthesis, and fruit yield and quality. A second aim was to analyse some of the mechanisms of photosynthetic down-regulation under drought, such as the capacity for ribulose-1,5-bisphosphate (RuBP) regeneration and Rubisco [ribulose-bisphosphate carboxylase] activity. Moderate irrigation improved plant water status, leaf photosynthesis and transpiration. Considering the results over ten years, soil water availability (estimated as pre-dawn leaf water potential, ψPD) largely determined leaf photosynthesis and leaf transpiration. Decreased photosynthesis was due to both stomatal and non-stomatal factors. The latter were related to decayed electron transport rate and reduced RuBP regeneration capacity, but not to decreased Rubisco activity. Moderate irrigation also improved grape yield, although this effect was much larger in Tempranillo than in Manto Negro. Moreover, the correlation between photosynthesis and grape yield was significant in Tempranillo, but not in Manto Negro. In contrast, the correlation between ψPD and several parameters reflecting fruit quality (such as soluble solids and total polyphenol content) was significant only in Manto Negro. These results suggest that there is a close link between water availability and grape yield, mostly through water stress effects on photosynthesis. Drought effects on grape quality are linked to water availability but not to photosynthesis or yield.
|Pages:||607 - 619|
|Journal:||Functional Plant Biology|
canopy, crop quality, crop yield, cultivars, drought,drought resistance, electron transfer, enzyme activity, enzymes, fruits,grapes, irrigation, leaf water potential, leaves, photosynthesis,polyphenols, ribulose-bisphosphate carboxylase, soil water, stomata,stress, stress response, transpiration, water availability, waterstress, Spain, Vitis, Vitis vinifera, Vitidaceae, Rhamnales,dicotyledons, angiosperms, Spermatophyta, plants, eukaryotes, Vitis,Southern Europe, Europe, Mediterranean Region, Developed Countries,European Union Countries, OECD Countries, carbon assimilation, carbondioxide fixation, crown cover, cultivated varieties, drought tolerance,electron flow, electron transport, leaf canopy, ribulose-1,5-diphosphatecarboxylase, ribulose-1,5-diphosphate oxygenase, soil moisture,Vitaceae, watering, Horticultural Crops (FF003) (New March 2000), PlantBreeding and Genetics (FF020), Plant Physiology and Biochemistry(FF060), Plant Water Relations (FF062), Plant Production