Plant reproductive strategies under environmental stress
Culley, Theresa .
Differential expression of chasmogamy and cleistogamy in light-limited environments.
As sedentary organisms, plants must respond quickly and adapt to changing environments in order to survive. One of the best known examples of such adaptation is the chasmogamous/cleistogamous breeding system in which both open, showy chasmogamous (CH) flowers and closed, self-pollinated cleistogamous (CL) flowers are produced on the same individual. This occurs largely in response to changing resource levels that vary either temporally or spatially. For example, many species of Viola begin to flower in the early spring in response to warming soil temperature and/or increasing day length. CH flowers are produced first before tree leaf-out when light levels are high and insect pollinators are most frequent; CL flowers subsequently appear only after the forest canopy forms when light levels and pollinator activity dramatically decline. Because of this dependence of flowering on environmental variation, changes in availability of a resource such as light can shift relative windows of CH and CL flower production, thereby indirectly impacting the mating system (i.e. relative rates of outcrossing and outcrossing). This may lead to changes in the genetic composition and structure of populations over time, potentially impacting the evolutionary ability of populations to continue to adapt to environmental changes. Given the ability of global climate change to promote shifts in early flowering of temperate forest herbs as well impacts on insect activity, it is likely that differential expression and reproductive output of CH and CL will be changed as well. This presentation will emphasize the importance of considering not only shifts in flowering in response to global climate change and environmental stress, but also the finer-scale effects such actions may have on the mating system and population genetic structure of plant species around the world.
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1 - University Of Cincinnati, Department Of Biological Sciences, 614 Rieveschl Hall, Cincinnati, OH, 45221-0006, USA
Presentation Type: Symposium or Colloquium Presentation
Location: Westminster Room/Chase Park Plaza
Date: Wednesday, July 13th, 2011
Time: 11:35 AM