Recent Topics Posters
Mudd, Samuel J , Jorgensen, Rachael , Seshadri, Arathi .
Hot and Dry: Tradeoffs in floral traits in response to temperature and water stress.
Global climate change is causing rapid, unprecedented variations in the environment including temperature increases, altered precipitation patterns etc. which affect major biological processes. Plants being sessile are obligated to respond rather rapidly to these variations. Any change in the normal growing environment is a stressful condition and plants respond by modifying vegetative and floral traits. Alteration to floral characteristics affects reproductive success and influences individual fitness. Knowledge of plant stress responses will enable us to understand the nature of adaptability and evolutionary potential of plants. Environmental variations are predicted to result in a range of responses in plants but it is not immediately clear whether the nature of response is independent of the kind of stress. In this study, we compare effects of water and temperature stress on floral traits in a hermaphroditic annual, Collinsia heterophylla (Plantaginaceae) whose native range is southern California but the species is common in seed mixes for gardens across the United States. Our results indicate that plants in the warm treatment flowered significantly earlier, had a narrower peak flowering duration and smaller flowers. Water stress did not affect days to flowering and other floral traits, but total flowering duration in well-watered plants was twice that of water-stressed plants. Analyses of gametophytic traits revealed that pollen viability was not influenced by stress but warm treatment plants had higher per capita ovule numbers. Taken together, these findings suggest that temperature and water stress elicit differential responses in traits affecting reproductive success. Although reproductive phase is one of the most vulnerable stages during plant development it is also the stage when selection acts to favor beneficial characteristics. Ongoing studies on floral longevity, comparison of stress-mediated selfing and out-crossing success and inbreeding depression will provide a better understanding of reproductive strategies in plants responding to environmental stress.
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1 - Colorado State University, Biology, Fort Collins, CO, 80523, USA
Presentation Type: Recent Topics Poster
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM