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Abstract Detail


Pollination Biology

Jabbari, Shabnam [1], Davis, Sandra L. [2].

Flower Color Variability and Mixed Mating in the Protandrous Herb Saponaria officinalis (L. Caryophyllaceae).

The perennial herb Saponaria officinalis is protandrous; within a flower, anthers dehisce before stigmas are receptive. Theory predicts this type of breeding system may have evolved to prevent self-fertilization and inbreeding depression. However, overlap between gender stages may allow for self-fertilization, resulting in a mixed mating system. The high frequency of mixed mating systems found in nature is intriguing, as theoretical models have predict plants will evolve to complete outcrossing or selfing. However, a mixed mating system in which selfing is delayed until opportunities for outcrossing have passed, provides the genetic benefits of outcrossing and the reproductive assurance of selfing. Prior studies have shown that pollinators are important in the reproduction of S. officinalis but flowers may still self-fertilize. Flowers of S. officinalis vary from white to pink; corresponding with the gender development of the flower. Color variability may affect pollinator visitation and preference. Therefore, to understand the evolution of mixed mating in S. officinalis, it is necessary to understand the interaction between these variables. Flower color may be a genetically determined trait and differ between populations. In addition, it is believed that sun exposure has an effect on the concentration of the anthocyanin. In this study, plants from five populations were transplanted into a common garden. UV exposure was then manipulated on half of the plants by using 50% shade-cloth. Flowers from each plant were collected at four different stages of gender. Anthocyanins were extracted from the petals and its concentration was determined by measuring absorbance using a spectrophotometer. Pollinator observations were conducted at various times throughout the day to observe pollinator visitation and gender preference. The data was analyzed using a mixed model ANOVA to determine if 1) there are population-level differences in flower color; 2) flower color is affected by environmental factors and 3) the change in color over the gender development of the flower is affected by either the population or environmental factors.

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1 - University of Indianapolis, Biology, 1400 E. Hanna Ave., Indianapolis, IN, 46227
2 - University of Indianapolis, Biology, 1400 E. Hanna Ave., Indianapolis, IN, 46227, USA

Keywords:
mixed mating system
reproductive assurance
pollinator limitation
Floral color.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall A/Convention Center
Date: Monday, August 2nd, 2010
Time: 5:30 PM
Number: PPL004
Abstract ID:557


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