Articles
WATER USE EFFICIENCY DURING DROUGHT AND RECOVERY IN GRAPEVINES: DIFFERENTIAL BEHAVIOUR OF THREE CULTIVARS
Article number
931_13
Pages
127 – 135
Language
English
Abstract
A comparative study on water-use-efficiency (WUE) under severe water deficit and recovery was conducted on potted grapevines of Grenache, Syrah and Chardonnay cultivars grown in Mallorca (Spain). Deficit irrigation was established according to the leaf maximum daily gs to achieve severe water deficit conditions in the lapse of one week.
The goal was to analyze how gs is regulated under water stress and recovery, as well as how water stress affects the adjustments of WUE at leaf and whole plant level.
Soil water content, climatic conditions, leaf photosynthesis, transpiration, gs and mesophyll conductance (gm) were recorded daily throughout the experiment.
Water relations and plant hydraulic conductivity (KhPlant), were performed on five specific sampling days: the day the desired stomatal conductance (50 mmol m-2 s-1) was first achieved (day 0), seven days after sustaining the plants at constant soil moisture, just before re-watering (day 7), and then 1, 2 and 7 days after re-watering.
The relative contribution of gs and gm limitations during acclimation to water stress changes from predominant gs early during water stress to similar gs and gm after acclimation.
Nonetheless during re-watering photosynthesis recovery was mostly limited by gs, since stomatal closure recovered much more slowly than gm. Water stress induced an increase in WUE, which interestingly persisted many days after re-watering.
KhPlant variations during drought and recovery were in accordance with gs values.
However, the relationship with gm variations was lower.
Chardonnay showed the largest differences between water stress and irrigated plants and the lowest leaf water potential.
Under drought and recovery this cultivar maintained lower gs and leaf photosynthesis (AN) but their WUE values were not the highest.
The goal was to analyze how gs is regulated under water stress and recovery, as well as how water stress affects the adjustments of WUE at leaf and whole plant level.
Soil water content, climatic conditions, leaf photosynthesis, transpiration, gs and mesophyll conductance (gm) were recorded daily throughout the experiment.
Water relations and plant hydraulic conductivity (KhPlant), were performed on five specific sampling days: the day the desired stomatal conductance (50 mmol m-2 s-1) was first achieved (day 0), seven days after sustaining the plants at constant soil moisture, just before re-watering (day 7), and then 1, 2 and 7 days after re-watering.
The relative contribution of gs and gm limitations during acclimation to water stress changes from predominant gs early during water stress to similar gs and gm after acclimation.
Nonetheless during re-watering photosynthesis recovery was mostly limited by gs, since stomatal closure recovered much more slowly than gm. Water stress induced an increase in WUE, which interestingly persisted many days after re-watering.
KhPlant variations during drought and recovery were in accordance with gs values.
However, the relationship with gm variations was lower.
Chardonnay showed the largest differences between water stress and irrigated plants and the lowest leaf water potential.
Under drought and recovery this cultivar maintained lower gs and leaf photosynthesis (AN) but their WUE values were not the highest.
Authors
A. Pou, J. Flexas, S. Martorell, M. Tomàs , H. Medrano
Keywords
Vitis vinifera, water stress, photosynthesis, stomatal conductance, whole plant hydraulic conductivity
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