Analyzing drought resistance in plants by combining whole-plant experiments and computer modeling /
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| Other Authors: | , , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1989.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | The combination of computer simulation models and whole-plant experiments is a powerful analytical technique that enhances our understanding of regulatory mechanisms controlling adaptation of plants. A computer model, Plant Water Dynamics, was developed to simulate the dynamic variations of water flows and water status in plants. The modeling approach was based on the notion that plant water status depends on the balance of three water fluxes: uptake of water from soil, water storage in plant tissue, and transpiration. These fluxes are calculated using water transport theory and the concepts of 'capacitance', 'effective leaf area', and 'morphological homeostasis'. Stress responses control the flow of water through the plant by affecting the conductances of roots, xylem and leaves. These stress responses are triggered as the water status of soil and plant deteriorate. The model allows for adaptation to stress by modifying some of the responses as the plant osmotically adjusts. The model was used to analyze the behavior of single vegetative plants of cowpea (Vigna unguiculata L. Walp.), sugarbeet (Beta vulgaris L.) and four cultivars of grain sorghum (Sorghum bicolor L. Moench) that were exposed to two soil water regimes under controlled environmental conditions: soil well watered by daily irrigation and soil allowed to dry by plant transpiration. Environmental conditions inside the chambers represented warm, humid, sunny days in Central Texas. Transpiration rates were monitored hourly during 12 to 16 days. Daily measurements of leaf area per plant, leaf water potential and leaf osmotic potential were taken. Simulations of transpiration of well watered plants suggested that the prodigal behavior of cowpea and sugarbeet, compared with the conservative behavior of sorghum, could be explained by a combination of higher maximum stomatal conductance and higher effective leaf area. Under water stress, cowpea conserved water by inhibiting transpiration and maintaining a high leaf water potential, while sugarbeet showed a more prodigal behavior, decreasing transpiration later than cowpea and failing to maintain a high leaf water potential... |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Agronomy." |
| Physical Description: | xviii, 194 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |