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Water potential components in growing citrus fruits
1Department of Plant Sciences, University of California, Riverside, California 92502.
Plant Physiology
|July 1, 1970
Summary
Navel orange fruit vesicles show stable osmotic potential, unaffected by transpiration or sugar movement. Other fruit tissues, like mesocarp, exhibit diurnal osmotic potential changes linked to water status.
Area of Science:
- Plant Physiology
- Fruit Biology
Background:
- Water and osmotic potentials are crucial for fruit development and quality.
- Understanding these potentials in different fruit tissues is key to managing crop yield and stress tolerance.
Purpose of the Study:
- To investigate the influence of transpiration and carbohydrate translocation on water and osmotic potentials within navel orange (Citrus sinensis) fruit tissues.
- To determine how anatomical isolation and vascular connections affect these potentials in vesicles, mesocarp, and exocarp.
Main Methods:
- Measurements of water and osmotic potentials in fruit tissues (vesicles, mesocarp, exocarp) under varying conditions.
- Stem girdling experiments to assess carbohydrate translocation effects.
- Analysis of diurnal changes and response to water deficit over 20 days.
Main Results:
- Fruit vesicles maintained consistent osmotic potential, isolated from transpiration and translocation changes.
- Mesocarp and exocarp tissues showed diurnal fluctuations in osmotic potential, correlating with transpiration rates.
- Stem girdling impacted mesocarp osmotic potential but not exocarp or vesicle potentials.
- Reduced exocarp water potential led to decreased osmotic potential in vesicles and exocarp, with varying turgor pressure responses.
Conclusions:
- Navel orange vesicles are osmotically independent of transpiration and carbohydrate translocation due to their anatomical isolation.
- Mesocarp and exocarp osmotic potentials are dynamic and responsive to environmental factors and water availability.
- Turgor pressure regulation in the exocarp may involve osmotic adjustment or measurement complexities.
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