| 1. |
- Eisen, Katherine E., et al.
(författare)
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Honest floral signalling traits vary across and within populations in an insect-pollinated plant
- 2023
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Ingår i: Functional Ecology. - 0269-8463. ; 37:9, s. 2511-2522
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Tidskriftsartikel (refereegranskat)abstract
- In flowering plants that produce concealed rewards, pollinator foraging preferences may select for floral advertisement traits that are correlated with rewards. To date, studies have not focused on the potential for honest signals to vary across populations, which could occur due to differences in pollinator communities or plant mating system. We tested for variation in honest signals across and within populations and mating systems in Arabis alpina, a broadly distributed arctic-alpine perennial herb that is visited by a variable community of insects. In a greenhouse common garden, we tested for correlations between corolla area, floral scent and nectar volume in 29 populations. In 12 field populations, we examined variation in pollen limitation and corolla area. Across and within populations and mating systems, larger flowers generally produced more nectar. Total scent emission was not correlated with nectar production, but two compounds—phenylacetaldehyde and benzyl alcohol—may be honest signals in some populations. Corolla area was correlated with pollen limitation only across populations. Our results suggest that honest signals may be similar across populations but may not result from contemporary direct selection on floral advertisements. Read the free Plain Language Summary for this article on the Journal blog.
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| 2. |
- Petrén, Hampus, et al.
(författare)
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Differences in mating system and predicted parental conflict affect post-pollination reproductive isolation in a flowering plant
- 2023
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Ingår i: Evolution; international journal of organic evolution. - : Oxford University Press (OUP). - 1558-5646 .- 0014-3820. ; 77:4, s. 1019-1030
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Tidskriftsartikel (refereegranskat)abstract
- Mating system shifts from outcrossing to selfing are frequent in plant evolution. Relative to outcrossing, selfing is associated with reduced parental conflict over seed provisioning, which may result in postzygotic, asymmetric, reproductive isolation in crosses between populations of different mating systems. To test the hypothesis that post-pollination reproductive isolation between populations increases with increasing differences in mating system and predicted parental conflict, we performed a crossing experiment involving all combinations of three self-compatible populations (with low outcrossing rates), and three self-incompatible populations (with high outcrossing rates) of the arctic-alpine herb Arabis alpina, assessing fitness-related seed and plant traits of the progeny. Predicted levels of parental conflict ("genome strength") were quantified based on strength of self-incompatibility and estimates of outcrossing rates. Crosses between self-compatible and self-incompatible populations yielded very small seeds of low viability, resulting in strong reproductive isolation. In 14 of 15 reciprocal between-population crosses, seeds were heavier when the paternal plant had the stronger genome, and seed mass differences between cross directions increased with an increased difference in parental conflict. Overall, our results suggest that, when sufficiently large, differences in mating system and hence in expected parental conflict may result in strong post-pollination reproductive barriers contributing to speciation.
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