The impact of self-incompatibility systems on the prevention of biparental inbreeding

Tara N. Furstenau, Reed Cartwright

Research output: Contribution to journalArticle

Abstract

Inbreeding in hermaphroditic plants can occur through two different mechanisms: biparental inbreeding, when a plant mates with a related individual, or self-fertilization, when a plant mates with itself. To avoid inbreeding, many hermaphroditic plants have evolved self-incompatibility (SI) systems which prevent or limit self-fertilization. One particular SI system-homomorphic SI-can also reduce biparental inbreeding. Homomorphic SI is found in many angiosperm species, and it is often assumed that the additional benefit of reduced biparental inbreeding may be a factor in the success of this SI system. To test this assumption, we developed a spatially-explicit, individual-based simulation of plant populations that displayed three different types of homomorphic SI. We measured the total level of inbreeding avoidance by comparing each population to a self-compatible population (NSI), and we measured biparental inbreeding avoidance by comparing to a population of self-incompatible plants that were free to mate with any other individual (PSI). Because biparental inbreeding is more common when offspring dispersal is limited, we examined the levels of biparental inbreeding over a range of dispersal distances. We also tested whether the introduction of inbreeding depression affected the level of biparental inbreeding avoidance. We found that there was a statistically significant decrease in autozygosity in each of the homomorphic SI populations compared to the PSI population and, as expected, this was more pronounced when seed and pollen dispersal was limited. However, levels of homozygosity and inbreeding depression were not reduced. At low dispersal, homomorphic SI populations also suffered reduced female fecundity and had smaller census population sizes. Overall, our simulations showed that the homomorphic SI systems had little impact on the amount of biparental inbreeding in the population especially when compared to the overall reduction in inbreeding compared to the NSI population. With further study, this observation may have important consequences for research into the origin and evolution of homomorphic self-incompatibility systems.

Original languageEnglish (US)
Article number4085
JournalPeerJ
Volume2017
Issue number11
DOIs
StatePublished - Jan 1 2017

Fingerprint

Inbreeding
inbreeding
Seed
Population
Self-Fertilization
inbreeding depression
selfing
Seed Dispersal
pollen flow
Angiosperms
Censuses
Population Density
Pollen
homozygosity
seed dispersal
cans
Fertility
Angiospermae
population size
fecundity

Keywords

  • Inbreeding depression
  • Isolation by distance
  • Mating system
  • Population genetics
  • Simulation

ASJC Scopus subject areas

  • Neuroscience(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)

Cite this

The impact of self-incompatibility systems on the prevention of biparental inbreeding. / Furstenau, Tara N.; Cartwright, Reed.

In: PeerJ, Vol. 2017, No. 11, 4085, 01.01.2017.

Research output: Contribution to journalArticle

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