Plant reproductive strategies under environmental stress
Seshadri, Arathi , Mudd, Samuel J .
A comparison of reproductive responses in plants growing under varying levels of temperature and water availability.
Unprecedented climatic changes over the last decade have resulted in plant species experiencing large variations in atmospheric CO2 levels, average temperatures and precipitation patterns. These variables are described as environmental stresses and plants experiencing such stressful conditions exhibit altered vegetative and reproductive traits either as plastic responses or genetic changes or both. Knowledge of stress-mediated responses, role of selection in the prevailing conditions and possible epigenetic changes can provide important insights into plant evolutionary potential. Increase in selfing is seen in plants adapting to changing environments with the predominant mechanism being a variation in floral traits facilitating autonomous selfing. Inbreeding depression, an associated cost of increased selfing can vary with stress and the nature of interaction between stress and inbreeding depression is not entirely resolved. Focusing on plasticity in the expression of floral traits facilitating selfing, we aim to understand the modulation of reproductive strategies and patterns of inheritance under varying levels of temperature and water-availability. Using greenhouse populations of Collinsia heterophylla, a hermaphroditic annual, we compared flower size, herkogamy and autonomous selfing success in experimental plants. While the onset of flowering and peak flowering duration are different under temperature and water stress, nature of variation in flower size is similar for both variables. Only temperature stress resulted in a significant reduction in herkogamy but autonomous selfing was higher in both temperature and drought stressed plants indicating that the floral trait known to be correlated with autonomous selfing success varies with the kind of stress. In conclusion, our results indicate that acclimation to temperature and water stress elicits differential responses in plants. Further analyses will explore the interaction between stress types and levels. Implications of our findings in relation to adaptation by increased selfing and inbreeding depression under stress will be discussed.
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1 - Colorado State University, Biology, 1878 Biology, Fort Collins, Colorado, 80523, USA
Presentation Type: Symposium or Colloquium Presentation
Location: Westminster Room/Chase Park Plaza
Date: Wednesday, July 13th, 2011
Time: 9:00 AM