The Evolutionary Dynamics of Conflicts of Interest in Plant Mating Systems

The diversity of flowering plants -angiosperms- on planet Earth is nearly matched by the diversity of mating systems and floral traits they exhibit. Since Darwin evolutionary biologists have been fascinated by this diversity and worked to explain and understand it. In this thesis I focus on aspects of the diversity in plant reproductive biology that is driven by conflicts. Chapter 1 explores intergenomic conflict by investigating the role cytoplasmic male sterility (CMS) plays in driving biparental inheritance of mitochondria in angiosperms. Flowering plants are predominantly hermaphrodites and mitochondria is typically inherited by a single parent in all sexual eukaryotes. This lays the ground for a conflict between the nuclear genome, which is inherited in the usual Mendelian fashion and the uniparentally inherited mitochondrial genome. In their seminal text Genes in Conflict Burt and Trivers (2006) hypothesized that this system ought to lead to the evolution of paternal inheritance of mtDNA and in this chapter I demonstrated that this is likely the case. In Chapter 2 I investigate a conflict of interest flowering plants experience when the pollinators they have co-evolved with for tens of millions of years are co-opted by sterilizing pathogens, such as the well studied anther smuts. Plants in such a scenario must balance how they invest their resources to attract pollinators - needing to be attractive to pollinators in order to reproduce but trying to mitigate the risk of being sterilized by the pathogens these pollinators are vectors of. In this chapter I demonstrated that within stressful environments with high turnover and strong density dependent regulation on recruitment this balance tips in favour of high investment in attractive floral traits. Mathematical modelling has provide an invaluable tool for evolutionary biologists for well over a century; models of population genetics predate our molecular understanding of genes. Following this rich tradition I leveraged both simulation (Chapter 1) and analytical (Chapter 2) techniques in order to enrich our understanding of these conflict-driven aspects of plant reproductive biology.<p></p>

Author dc:creator

• Zak Bowden (21048461)

• Uncategorised value

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• All rights reserved

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10779/exe.32896769.v1

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oai:figshare.com:article/32896769