Genetic variation of ecophysiological traits in two gynodioecious species of Schiedea (Caryophyllaceae)

Authors

  • Theresa M. Culley,

    Corresponding author
    1. Department of Ecology and Evolutionary Biology, University of California Irvine, California 92697, USA; Present address: Department of Biological Sciences, University of Cincinnati, 614 Rieveschl Hall, Cincinnati, OH 45221-0006 USA,
    • Author for correspondence: Theresa M. Culley Tel: +1 513 556 9705 Fax: +1 513 556 5299 Email: theresa.culley@uc.edu

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  • Amy K. Dunbar-Wallis,

    1. Department of Ecology and Evolutionary Biology, University of California Irvine, California 92697, USA; Present address: Department of Biological Sciences, University of Cincinnati, 614 Rieveschl Hall, Cincinnati, OH 45221-0006 USA,
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  • Ann K. Sakai,

    1. Department of Ecology and Evolutionary Biology, University of California Irvine, California 92697, USA; Present address: Department of Biological Sciences, University of Cincinnati, 614 Rieveschl Hall, Cincinnati, OH 45221-0006 USA,
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  • Stephen G. Weller,

    1. Department of Ecology and Evolutionary Biology, University of California Irvine, California 92697, USA; Present address: Department of Biological Sciences, University of Cincinnati, 614 Rieveschl Hall, Cincinnati, OH 45221-0006 USA,
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  • Masako Mishio,

    1. Present address: River Basin Research Center, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan
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  • Diane R. Campbell,

    1. Department of Ecology and Evolutionary Biology, University of California Irvine, California 92697, USA; Present address: Department of Biological Sciences, University of Cincinnati, 614 Rieveschl Hall, Cincinnati, OH 45221-0006 USA,
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  • MaryKay Herzenach

    1. Department of Ecology and Evolutionary Biology, University of California Irvine, California 92697, USA; Present address: Department of Biological Sciences, University of Cincinnati, 614 Rieveschl Hall, Cincinnati, OH 45221-0006 USA,
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Summary

  • • Evolution of dimorphic breeding systems may involve changes in ecophysiological traits as well as floral morphology because of greater resource demands on females. Differences between related species suggest that ecophysiological traits should be heritable, and species with higher female frequencies should show greater sexual differentiation.
  • • We used modified partial diallel crossing designs to estimate narrow-sense heritabilities and genetic correlations of sex-specific ecophysiological and morphological traits in closely related gynodioecious Schiedea salicaria (13% females) and Schiedea adamantis (39% females).
  • • In S. salicaria, hermaphrodites and females differed in photosynthetic rate and specific leaf area (SLA). Narrow-sense heritabilities were significant for stomatal conductance, SLA and inflorescence number in hermaphrodites, and for SLA and inflorescence number in females. Schiedea adamantis had no sexual dimorphism in measured traits; stomatal conductance, stem number and inflorescence number were heritable in females, and stem number was heritable in hermaphrodites. In both species, significant genetic correlations of traits between sexes were rare, indicating that traits can evolve independently in response to sex-differential selection. Significant genetic correlations were detected between certain traits within sexes of both species.
  • • Low heritability of some ecophysiological traits may reflect low additive genetic variability or high phenotypic plasticity in these traits.

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