| Abstract Detail
Reproductive Processes Kwok, Allison [1], Dorken, Marcel [2]. The measurement of sexual selection in modular organisms: patterns of mating and reproductive success in the clonal plant Sagittaria latifolia (Alismataceae). Instantaneous measures of fitness scale with size in modular organisms. However, for these organisms, size is largely determined by non-heritable variation (age and local resource conditions), obscuring patterns of heritable variation in fitness. Among clonal plants, modularity is expressed in a hierarchical manner, and size can vary among individuals at the shoot and whole-clone level. Size variation at both of these levels can influence mating and reproductive success by affecting flower (and gametophyte) production and the size of local mating neighbourhoods. We aimed to measure patterns of sexual selection (non-random variation in mating success) in the clonal plant Sagittaria latifolia by taking into account variation in shoot and clone size. This plant is unusual among flowering plants in that populations consist of either hermaphrodites (monoecious populations) or females and males (dioecious populations). We measured the magnitude of sexual selection in two natural populations (one monoecious and one dioecious population) using Bateman gradients (ßss). These gradients were calculated using parentage analysis, which was inferred from the segregation of alleles at seven SSR (microsatellite) loci. We used residual regressions to account for the effect of shoot and clone size on mating and reproductive success to calculate ßss. In both populations, when controlling for size, we found significant linear associations between mating and reproductive success for males (and male function in hermaphrodites) but not for females (or female function), indicative of stronger sexual selection through male than through female function in these populations. However, measures of sexual selection that did not control for variation in plant size revealed positive sexual selection in both sexes, driven by a strong association between plant (shoot and clone) size, and mating and reproductive success in both populations. Because of trade-offs between the size and number of shoots in clonal plants, our results provide insights into the evolution of plant life histories in response to sexual selection.
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1 - Trent University, Environmental And Life Sciences, 1600 West Bank Dr., ENLS ESB A211, Peterborough, ON, K9L 0G2, Canada
2 - Trent University, Biology, 1600 West Bank Drive, Peterborough, ON, K9J 0G2, Canada
Keywords:
sexual selection
clonality
evolution
sexual system
fitness.
Presentation Type: Oral Paper
Session: RP1, Reproductive Processes 1
Location: /
Date: Thursday, July 22nd, 2021
Time: 10:00 AM(EDT)
Number: RP1001
Abstract ID:878
Candidate for Awards:None |
