Hughes , P. William , Simons, Andrew .
Phenotypically plastic semelparity in Lobelia inflata.
Semelparous organisms are defined by their reproductive life history: reproductive occurs once and is fatal. However, the bout or reproduction that semelparous organisms undertake may stretch over a long period of time, and the quality of offspring is not constant. No studies have yet specifically focused on how semelparous organisms invest reproductive effort.
We hypothesize that norms of reaction for reproductive allocation will favor strategies that emphasize semelparous behaviour when plants are near the end of their lives (late in the season). To address this prediction, we use the monocarpic (semelparous) self-fertilizing biennial Lobelia inflata (Campanulaceae) to examine how phenotypically plastic reproductive allocations patterns are. From 2008-10, we manipulated the length of growing season in successive assemblages of plants to mimic the effect that late bolting and delayed reproduction have on the allocation function of the individual. We found that genetically identical individuals have different reproductive allocation patterns when they bolt at different points over the growing season. In this presentation, we will show data indicating that (1) late-bolting individuals reproduce more simultaneously than early-bolters ; (2) that early-bolters, even when controlled for resource availability, are more likely to have unrealized reproductive potential; and (3) that within an individual plant, early fruits mature more slowly and contain fewer, larger seeds, showing an early bias in offspring quality.
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1 - Carleton University, Biology, 227 Nesbitt Building, 1125 Colonel By Drive, Ottawa, ON, K1S5B6, Canada
2 - Carleton University, Nesbitt 209, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
Presentation Type: Oral Paper:Papers for Sections
Location: Union B/Hyatt
Date: Tuesday, July 10th, 2012
Time: 8:30 AM