Corso di Laurea Magistrale in Scienze viticole ed enologiche - SVE

To learn about the relationships between grapevine physiology and inputs from agriculture practices, upon both cultivation standards and abiotic limiting conditions.

The students will integrate the knowledge acquired both by following the course programme and by examining scientific literature.

In-itinere aninimous tests

Water metabolism: physiological role.

Concept of water potential as an energy index.

 

Measurement of water potential: in the leaf, in the shoot, pre-dawn, at mid-day.

The analogy of the Ohm Law to study water fluxes in plant.

The continuum of water flow along soil-plant-atmosphere.

How to modelize hydraulic resistances in grapevine organs.

Implication of cell water metabolism on grapevine water balance:
osmoregulation; symplasm/apoplasm water exchange; aquaporin role.

 

Time scaling relationships between water potential and transpiration:
occurrence of water stress; occurrence of rain; diel fluctuations; seasonal fluctuations; in different water-holding soils.

Plant water balance:
isohydric response to water stress;
anisohydric response.

 

Measurement of hydraulic conductance (in the root, in the shoot, in the leaf, in the whole plant).

The evaporative flux method to estimate hydraulic resistances in grapevine organs.

The high-pressure-flow-meter:
principles;
measurements of embolism extent;
estimation of aquaporin role in controlling plant hydraulics.

Root water absorption and transport:
symplasm, apoplasm and cell-to-cell water pathways;
hormonal control at budbreak;
soil temperature and seasonal control.

 

Abscisic acid biosynthesis in root:
activation by pH; influence of water stress; influence of root respiration; split-root experiments and partial root drying.

Abscisic acid root-to-shoot control:
implications in rootstocks;
auxin/ABA interaction for root deepening and later root emergence;
soil properties (clay) modulate ABA response.

Water transport in rootstocks:
induction of tolerance to water stress (mechanisms and genotypes related);
Induction of stress avoidance (mechanisms and genotypes related);
hormonal control of aquaporin activation;
vigor induction and water metabolism.

 

Auxin control of vascular development.

Model of auxin translocation:
auxin control on apex dominance in grapevine;
auxin control on tropisms in grapevine.

Water (sap) transport in the shoot:
embolism formation;
embolism refilling;
role of aquaporins;
hormonal control of aquaporin activation;
adjustments in relation to upward and downward shoot growth orientation.

 

Transpiration :
the vapor pressure deficit (VPD) as energy determinant.

Atmospheric demand of transpiration.

Kinetics of temperature and relative humidity.

Environmental control of transpiration (microclimatic influences and viticultural issues).

Stomatal opening and closure (physiology of guard cells).

Stomatal control (regulation during water stress and CO₂ feedbacks).
VPD influence on ABA metabolism. ABA catabolism at its site of action allows optimization of gas exchange to current environmental conditions

 

Measurements of leaf gas exchange:
the infra-red gas analyzer;
measurement of stomatal conductance.

Photosynthesis; Photorespiration; Photoinhibition:
measurement of chlorophyll fluorescence.

Limitations to photosynthesis in grapevine:
water stress;
stomatal regulation;
light deficiency;
light excess;
temperature;
leaf ageing;
in sun and shadow leaves;
shoot orientation;
sink sucrose downloading;
starch accumulation in leaf.

 

 

Keller M. The Science of Grapevines: Anatomy and Physiology, Elsevier Academic Press, 2010.
Leclerc J-C. Plant Ecophysiology. Science Publishers Inc., 2003.

Taiz Zeiger. Plant Physiology. Piccin 2014

Taiz, Zeiger. http://5e.plantphys.net

Class in Alba