EXPERIMENTAL STUDIES ON THE FUNCTIONAL SIGNIFICANCE OF HETEROSTYLY

@article{Kohn1992EXPERIMENTALSO,
  title={EXPERIMENTAL STUDIES ON THE FUNCTIONAL SIGNIFICANCE OF HETEROSTYLY},
  author={Joshua R. Kohn and Spencer C. H. Barrett},
  journal={Evolution},
  year={1992},
  volume={46}
}
Heterostyly has been viewed as both an antiselfing device and a mechanism that increases the proficiency of pollen transfer between plants. We used experimental manipulation of the morph structure of garden populations of self‐compatible, tristylous Eichhornia paniculata to investigate the function of floral polymorphism. Outcrossing rates (t), levels of intermorph mating (d), and morph‐specific male and female reproductive success were compared in replicate trimorphic and monomorphic… 
Female reproductive success and the evolution of mating-type frequencies in tristylous populations.
TLDR
These results suggest that interactions between mating patterns and female fertility are responsible for variation in morph frequencies and loss of the M-morph from tristylous populations of N. triandrus.
Evolution and maintenance of stigma-height dimorphism in Narcissus. II. Fitness comparisons between style morphs
TLDR
A mating model that incorporates the genetics of stigma-height dimorphism and contrasting rates of assortative and disassortative mating in the style morphs demonstrated that stigma- height dimorphistan will always be maintained when levels of disassORTative mating are greater than assortation mating, and that the observed L-biased populations in Narcissus spp.
POLLEN DISCOUNTING AND THE SPREAD OF A SELFING VARIANT IN TRISTYLOUS EICHHORNIA PANICULATA: EVIDENCE FROM EXPERIMENTAL POPULATIONS
  • J. KohnS. Barrett
  • Environmental Science
    Evolution; international journal of organic evolution
  • 1994
TLDR
It is indicated that floral traits that alter the selfing rate can have large and context‐dependent influences on outcross pollen donation.
Frequency–dependent variation in reproductive success in Narcissus: implications for the maintenance of stigma–height dimorphism
TLDR
Patterns indicate that in the absence of physiological barriers to intra–morph mating, negative frequency–dependent selection contributes to the maintenance of stylar polymorphism through inter–morph pollen transfer.
Mating pattern of a distylous primrose in a natural population: unilateral outcrossing and asymmetric selfing between sexual morphs
TLDR
A mathematical model of the overdominance hypothesis is built to confirm that it is logically sound and is consistent with the explanation that distyly in this species is maintained either by overDominance due to previously reported recessive lethal effects of the thrum allele or by effectively dioecious mating if inbreeding depression is strong.
Floral manipulations reveal the cause of male fitness variation in experimental populations of Eichhornia paniculata (Pontederiaceae)
TLDR
Observations of pollinators and floral manipulations of genetically marked plants in experimental populations were used to evaluate three potential causes of differential siring success: pollinators prefer the S morph leading to higher male success; long styles interfere with pollen pick-up by insect visitors; and pollen from long-level anthers of the S Morph sires more seeds on the M morph than pollen from short-levelAnthers from the L morph.
POPULATION STRUCTURE AND MORPH‐SPECIFIC FITNESS DIFFERENCES IN TRISTYLOUS LYTHRUM SALICARIA
  • J. ÅgrenL. Ericson
  • Environmental Science
    Evolution; international journal of organic evolution
  • 1996
TLDR
To examine whether deviations from even morph frequencies can be explained by among‐morph differences in reproductive success, quantified flower and seed production in six and three populations in the northern and southern archipelago, respectively, and recorded segregation ratios in offspring produced in six trimorphic populations inThe northern area.
Postpollination discrimination between self and outcross pollen covaries with the mating system of a self-compatible flowering plant.
TLDR
The finding that stigmatic pollen-load capacity and stylar-discrimination ability contributed significantly to explaining the wide range of outcrossing rates in E. paniculata suggests that postpollination mechanisms play an important role in governing mating patterns in this species.
Mating patterns and demography in the tristylous daffodil Narcissus triandrus
TLDR
There were no consistent differences among the style morphs in outcrossing or biparental inbreeding indicating that the maintenance of trimorphism vs dimorphism is unlikely to be associated with inbreeding of maternal parents.
GENETIC CONSTRAINTS ON THE INDEPENDENT EVOLUTION OF MALE AND FEMALE REPRODUCTIVE CHARACTERS IN THE TRISTYLOUS PLANT LYTHRUM SALICARIA
TLDR
No evidence of negative genetic correlations appeared that would suggest trade‐offs and that could augment a selection response towards sexual specialization were found, suggesting that selection might not be able to act independently on biomass allocation to male and female flower parts.
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TLDR
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TLDR
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TLDR
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TLDR
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