“Sexual Traits are not Markedly Vestigialized in Asexual Populations of Decondon verticillatus (Lythraceae)”
International Journal of Plant Sciences, 179(8): 603-615, October 2018
SCI 236
Transitions from sexual to asexual reproduction are predicted to be accompanied by the reduction and developmental disintegration of sexual traits that no longer maintain fitness. While such transitions are common in plants, the evolutionary fate of sexual traits in derived asexual populations remains largely unknown, especially in species where the loss of sex is not confounded with a change in ploidy. In the tristylous wetland plant Decodon verticillatus, populations polymorphic for style length are sexual, while monomorphic populations are typically asexual under field conditions. Methodology. We compared ploidy, per-ramet flower production, flower size, and floral developmental stability between 22 monomorphic asexual populations and 26 polymorphic sexual populations distributed across the northern half of the species range in the Great Lakes region of North America. Pivotal results. Flow cytometry revealed that all populations were diploid—except for one monomorphic population that exhibited nuclear DNA content consistent with triploidy, which is known to cause sexual sterility. After accounting for the potential effects of temperature during flowering on floral development, we found that ramets in asexual populations produced ~50% (although not quite significantly) fewer flowers than those in sexual populations. Flowers varied widely in size among populations but were not smaller in asexual populations. Developmental stability of flowers was not lower in asexual populations than in sexual populations, although among monomorphic populations stability was lowest in populations for which confidence in exclusive asexuality was highest. Conclusions. Sex has been lost repeatedly across the northern range edge of D. verticillatus via at least two genetic pathways. Yet investment in and developmental stability of sexual traits is not consistently, and rarely significantly, reduced. The observation that no asexual genotype of D. verticillatus is widespread suggests that asexual populations do not persist long—perhaps only long enough to exhibit the very first stages of sexual vestigialization.
Description Source: International Journal of Plant Sciences. Published 2018 (8).
Authors
Corrina N. Thomsen is a PhD student in Biology at The University of British Columbia. She studies the landscape ecology of mucorrhizal fungi and their interactions with tree ranges. Her thesis advisor is Jason Pither (Biology).
Magdalena Bartkowska is a researcher at Queen’s University.
Chris Eckert is a professor of plant evolution and population ecology at Queen’s University.
UBC Library Holdings
How to Purchase this Journal
International Journal of Plant Sciences
ISSN 1058-5893
UBC Okanagan Classroom Artwork Project
The University of British Columbia Okanagan Classroom Artwork Project aims to display academically inspiring artwork in classrooms and other teaching areas of the university.
Artwork displayed as part of this project – including the covers of books and journals containing work written or edited by UBCO scholars and researchers – is intended to help enliven university teaching spaces, educate classroom users about the connections between research and teaching, and introduce members of the broader public to some of the research and scholarship carried out at UBCO.
How to Submit Artwork
If you know of other book or journal covers, or other academically inspiring artwork that is connected to work carried out by UBCO artists, scholars or researchers and that is consistent with UBCO’s educational mission, please email your suggestions to classroom.artwork@ubc.ca.
The UBC Okanagan Classroom Artwork Project began in 2019 with support from the Irving K. Barber School of Arts and Sciences. It is now a joint project of UBCO’s Faculties and the Office of the Provost.
Artwork and other images that are a part of this project are displayed solely for educational purposes.