Abstract Detail

Reproductive Processes

Christopher, Dorothy [1], Karron, Jeffrey [2], Mitchell, Randall [3], Trapnell, Dorset [4], Semski, Wendy [5], Porcher, Emmanuelle [6], Devaux, Celine [7].

Evolution of selfing rate in flowering plant populations.

A major conceptual challenge for evolutionary theory is the frequent occurrence of intermediate rates of self-fertilization in flowering plant populations. This pattern in nature is not consistent with classical genetic models, which predict that disruptive selection will cause intermediate selfing rates to be rare and transitory. Populations with low inbreeding depression should evolve predominant selfing because more maternal alleles are transmitted through self-fertilized seeds than through outcross seeds. By contrast, populations with high inbreeding depression should evolve predominant outcrossing because the transmission advantage of selfing is offset by the reduced fitness of selfed offspring. Since populations with intermediate selfing rates are common, researchers have sought to develop and test models that explore conditions favoring stable mixed mating.
Many selfing rate models explore whether a highly selfing morph could invade an outcrossing population. However, there are surprisingly few empirical studies characterizing variation in selfing rates within populations. Studies linking individual variation in selfing rate to variation in heritable floral traits can enable us to better understand the role of natural selection in the evolution of plant mating systems. Through the use of unambiguous paternity assignment, we are quantifying selfing rates of individual monkeyflower (Mimulus ringens) plants. Floral traits of this bumble bee-pollinated wetland perennial vary widely within populations, and heritabilities of traits such as flower size and anther-stigma separation are high (0.4 to 0.6). We are testing the hypothesis that selfing rate variation has an underlying genetic basis, and that it is strongly influenced by floral trait variation.  We then use these parameters in a new model that assesses the stability of mixed mating in flowering plant populations.

1 - UW-Milwaukee, Dept of Bio Sci, P.O. Box 413, Milwaukee, Wisconsin, 53211, United States
2 - University Of Wisconsin-Milwaukee, Department Of Biological Sciences, Po Box 413, Milwaukee, WI, 53201, United States
3 - University Of Akron, Department Of Biology, Dept Of Biology, Akron, OH, 44325, United States
4 - University of Georgia, Plant Biology, 2502 Miller Plant Sciences, 120 Carlton St., Athens, GA, 30602, USA
5 - UW-Milwaukee, Dept of Bio Sci, P.O. Box 413, Milwaukee, Wisconsin, 53201-0413, United States
6 - MNHN, Ecology Center, 61 Rue Buffon, Paris, France
7 - University of Montpellier, ISEM, Montpellier, France

selfing rate
mating system

Presentation Type: Oral Paper
Abstract ID:140
Candidate for Awards:None

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