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- Andersson, Stefan, et al.
(författare)
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Paternal effects on seed germination: a barrier to the genetic assimilation of an endemic plant taxon?
- 2008
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Ingår i: Journal of evolutionary biology. - : Wiley. - 1420-9101 .- 1010-061X. ; 21:5, s. 1408-1417
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Tidskriftsartikel (refereegranskat)abstract
- We used a crossing experiment to investigate post-zygotic barriers that might limit introgression between a pair of closely-related, gynodioecious plant species - the widespread weed Silene vulgaris and the local Swedish endemic S. uniflora ssp. petraea. The study not only considered the effects of hybridization on conventionally-used (primary) fitness components such as seed set and progeny survival, but also provided a test for the effects of interspecific hybridization on characters with more subtle or habitat-specific effects on fitness. We detected highly significant paternal effects on seed germination properties, with the germination characteristics of hybrid seed resembling those of the species that served as the pollen donor. These paternal effects on germination represent a potentially strong barrier to interspecific introgression in the two species' natural habitats, where an inappropriate germination response in the habitat of the maternal parent may lead to the failure of seedling establishment. Interspecific crosses had weak or variable effects on progeny survival, flowering and sex ratio, but these effects could not be interpreted in terms of barriers to introgression. Our results indicate that nuclear restorers in S. vulgaris have the capacity to suppress cytoplasmic male-sterility genes in its endemic congener.
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| 2. |
- Prentice, Honor C, et al.
(författare)
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Mosaic variation in allozyme and plastid DNA markers in the European ranges of Silene vulgaris and its partially sympatric relative S-uniflora (Caryophyllaceae)
- 2011
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Ingår i: Botanical Journal of the Linnean Society. - : Oxford University Press (OUP). - 1095-8339 .- 0024-4074. ; 166:2, s. 127-148
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Tidskriftsartikel (refereegranskat)abstract
- The perennial herbs Silene vulgaris and S. uniflora are closely related, partially sympatric and interfertile, yet morphologically distinct. We used nuclear (allozyme) and plastid (polymerase chain reaction-restriction fragment length polymorphism) DNA markers to investigate whether these species have a shared history of postglacial colonization and hybridization in Europe, as inferred from large-scale patterns of geographic variation. The majority of plastid haplotypes and allozyme alleles were widespread and patchily distributed within both species and there was no geographic structure in the distributions of shared allozymes or haplotypes. The mosaic variation is consistent with a scenario in which repeated episodes of interspecific hybridization pre-dated the largely allopatric range expansion of the two species during the postglacial period. Our overall results are not consistent with a scenario of extensive hybridization and introgression during the postglacial range expansion of the species or within their current areas of sympatry, but we found some evidence for local, postglacial evolution and hybridization in the Baltic region. (C) 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 166, 127-148.
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