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Title: Investigating ecotypic differences in the response of stomata and plant fitness to environmental change
Author: Selebatso, Tebogo
ISNI:       0000 0004 2722 1444
Awarding Body: University of Sheffield
Current Institution: University of Sheffield
Date of Award: 2011
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Increases in global carbon dioxide, temperature and, in some latitudes, humidity are characteristic features of global climatic change. There is overwhelming consensus on the future increase of these environmental factors. How plants respond to these changes has important implications for the performance of both natural and agricultural systems. The aim of this project was to quantify the effects of carbon dioxide, temperature and relative humidity on morphological features and plant fitness of ecotypes of Arabidopsis thaliana, originating from different altitudes and geographical origins. Ecotypes of A. thaliana were grown in controlled environment chambers to assess the extent that genetic constraints influence phenotypic plasticity. The results showed a significant variation among the ecotypes and some of the variables assessed correlated with altitude of origin. Plant branch number and the length of fruits positively correlated with altitude of origin under elevated C02 and elevated humidity respectively. High altitude ecotypes showed decreased leaf area and also matured earlier in increased temperature and relative humidity. High altitude ecotypes also flowered earlier under elevated temperature. Stomatal density and epidermal cell density increased with CO2. Stomatal density showed a positive relationship with stomatal conductance and carbon isotope discrimination under elevated CO2• Both elevated temperature and relative humidity decreased stomatal density and epidermal cell density. The leaf area, floral stem height and inflorescence number increased under both elevated temperature and relative humidity. Elevated temperature also increased plant branch number. Plant fitness and reproductive phenology were significantly promoted under C02 enrichment and affected negatively under sub-ambient CO2. This study shows intra-specific variation between ecotypes of A. thaliana in response to environmental manipulation and therefore the extent of genetic constraints to acclimation processes. Such knowledge of plant responses to more than one variable under predicted environmental change particularly carbon dioxide, temperature and humidity is critical to preservation of vegetation both natural and agricultural.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available