Disassortative mating and the maintenance of sexual polymorphism in painted maple Journal Article

Author(s): Field, David L; Barrett, Spencer C
Article Title: Disassortative mating and the maintenance of sexual polymorphism in painted maple
Affiliation IST Austria
Abstract: Since Darwin's pioneering research on plant reproductive biology (e.g. Darwin 1877), understanding the mechanisms maintaining the diverse sexual strategies of plants has remained an important challenge for evolutionary biologists. In some species, populations are sexually polymorphic and contain two or more mating morphs (sex phenotypes). Differences in morphology or phenology among the morphs influence patterns of non-random mating. In these populations, negative frequency-dependent selection arising from disassortative (intermorph) mating is usually required for the evolutionary maintenance of sexual polymorphism, but few studies have demonstrated the required patterns of non-random mating. In the current issue of Molecular Ecology, Shang (2012) make an important contribution to our understanding of how disassortative mating influences sex phenotype ratios in Acer pictum subsp. mono (painted maple), a heterodichogamous, deciduous tree of eastern China. They monitored sex expression in 97 adults and used paternity analysis of open-pollinated seed to examine disassortative mating among three sex phenotypes. Using a deterministic 'pollen transfer' model, Shang et al. present convincing evidence that differences in the degree of disassortative mating in progeny arrays of the sex phenotypes can explain their uneven frequencies in the adult population. This study provides a useful example of how the deployment of genetic markers, demographic monitoring and modelling can be integrated to investigate the maintenance of sexual diversity in plants.
Keywords: Plants; Acer; dichogamy; heterodichogamy; paternity analysis; sexual polymorphism
Journal Title: Molecular Ecology
Volume: 21
Issue 15
ISSN: 0962-1083
Publisher: Wiley  
Date Published: 2012-08-01
Start Page: 3640
End Page: 3643
DOI: 10.1111/j.1365-294X.2012.05643.x
Open access: no