Goodwillie, Carol , Stewart, Emily .
Consequences of cleistogamy and chasmogamy in Triodanis.
The evolutionary explanation for the maintenance of cleistogamous (CH) and chasmogamous (CL) flowers in many plant species remains elusive. Two widely distributed subspecies of Triodanis perfoliata have diverged in their relative allocation to CH and CL flowers. As part of an investigation of the selective factors responsible for this divergence, we compared the fitness contribution of CH and CL flowers in the two species. Seeds were collected from each fruit type of each species in a zone of contact in Pitt County, NC, and offspring were raised in a growth room experiment to quantify and compare germination, survival, biomass and fruit production. We found no evidence in either species for a fitness advantage of CH flowers that would compensate for the greater expense of producing them. In fact, in one of the taxa, CL seeds germinated at a significantly higher rate than CH seeds. We found morphological evidence for hybridization in CH offspring, particularly of T. perfoliata ssp. biflora. We consider the implications of CH and CL strategies for the rate of hybridization between the taxa and its consequences.
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1 - East Carolina University, Biology , Mail Stop 551, Greenville, NC, 27858, USA
mating system evolution.
Presentation Type: Oral Paper:Papers for Topics
Location: Forsyth Room/Chase Park Plaza
Date: Tuesday, July 12th, 2011
Time: 8:00 AM