Abstract
Many regional floras contain a high proportion of recently introduced plant species. Occasionally, hybridization between an introduced species and another species (introduced or native) can result in interspecific gene flow. This may occur even in instances where the F(1) hybrid shows very high sterility, but occasionally produces a few viable gametes. We provide examples of gene flow occurring between some rhododendrons recently introduced to the British flora, and between an introduced and native Senecio species. Neutral molecular markers have normally been employed to obtain evidence of interspecific gene flow, but the challenge now is to isolate and characterize functional introgressed genes and to determine how they affect the fitness of introgressants and whether they improve adaptation to novel habitats allowing introgressants to expand the range of a species. We outline a candidate gene approach for isolating and characterizing an allele of the RAY gene in Senecio vulgaris, which is believed to have introgressed from S. squalidus, and which causes the production of ray florets in flower heads. We discuss the effects of this introgressed allele on individual fitness, including those that originate directly from the production of ray florets plus those that may arise from pleiotropy and/or linkage.
Full Text
The Full Text of this article is available as a PDF (216.7 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Abbott R. J., Forbes D. G. Extinction of the Edinburgh lineage of the allopolyploid neospecies, Senecio cambrensis Rosser (Asteraceae). Heredity (Edinb) 2002 Apr;88(4):267–269. doi: 10.1038/sj.hdy.6800038. [DOI] [PubMed] [Google Scholar]
- Arnold M. L. Anderson's paradigm: Louisiana irises and the study of evolutionary phenomena. Mol Ecol. 2000 Nov;9(11):1687–1698. doi: 10.1046/j.1365-294x.2000.01090.x. [DOI] [PubMed] [Google Scholar]
- Brown P. O., Botstein D. Exploring the new world of the genome with DNA microarrays. Nat Genet. 1999 Jan;21(1 Suppl):33–37. doi: 10.1038/4462. [DOI] [PubMed] [Google Scholar]
- Comes H. P., Abbott R. J. Molecular phylogeography, reticulation, and lineage sorting in Mediterranean Senecio sect. Senecio (Asteraceae). Evolution. 2001 Oct;55(10):1943–1962. [PubMed] [Google Scholar]
- Cubas P., Lauter N., Doebley J., Coen E. The TCP domain: a motif found in proteins regulating plant growth and development. Plant J. 1999 Apr;18(2):215–222. doi: 10.1046/j.1365-313x.1999.00444.x. [DOI] [PubMed] [Google Scholar]
- Cubas P., Vincent C., Coen E. An epigenetic mutation responsible for natural variation in floral symmetry. Nature. 1999 Sep 9;401(6749):157–161. doi: 10.1038/43657. [DOI] [PubMed] [Google Scholar]
- Ellstrand N. C., Schierenbeck K. A. Hybridization as a stimulus for the evolution of invasiveness in plants? Proc Natl Acad Sci U S A. 2000 Jun 20;97(13):7043–7050. doi: 10.1073/pnas.97.13.7043. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ellstrand N. C., Whitkus R., Rieseberg L. H. Distribution of spontaneous plant hybrids. Proc Natl Acad Sci U S A. 1996 May 14;93(10):5090–5093. doi: 10.1073/pnas.93.10.5090. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lowe A. J., Abbott R. J. Routes of origin of two recently evolved hybrid taxa: Senecio vulgaris var. hibernicus and York radiate groundsel (Asteraceae). Am J Bot. 2000 Aug;87(8):1159–1167. [PubMed] [Google Scholar]
- Luo D., Carpenter R., Copsey L., Vincent C., Clark J., Coen E. Control of organ asymmetry in flowers of Antirrhinum. Cell. 1999 Nov 12;99(4):367–376. doi: 10.1016/s0092-8674(00)81523-8. [DOI] [PubMed] [Google Scholar]
- Luo D., Carpenter R., Vincent C., Copsey L., Coen E. Origin of floral asymmetry in Antirrhinum. Nature. 1996 Oct 31;383(6603):794–799. doi: 10.1038/383794a0. [DOI] [PubMed] [Google Scholar]
- Marks S. L., Abbott J. A. Critical care cardiology. Vet Clin North Am Small Anim Pract. 1998 Nov;28(6):1567-93, x. doi: 10.1016/s0195-5616(98)50137-4. [DOI] [PubMed] [Google Scholar]
- Martinsen G. D., Whitham T. G., Turek R. J., Keim P. Hybrid populations selectively filter gene introgression between species. Evolution. 2001 Jul;55(7):1325–1335. doi: 10.1111/j.0014-3820.2001.tb00655.x. [DOI] [PubMed] [Google Scholar]
- Milne R. I., Abbott R. J. Origin and evolution of invasive naturalized material of Rhododendron ponticum L. in the British isles. Mol Ecol. 2000 May;9(5):541–556. doi: 10.1046/j.1365-294x.2000.00906.x. [DOI] [PubMed] [Google Scholar]
- Mooney H. A., Cleland E. E. The evolutionary impact of invasive species. Proc Natl Acad Sci U S A. 2001 May 8;98(10):5446–5451. doi: 10.1073/pnas.091093398. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rieseberg L. H., Archer M. A., Wayne R. K. Transgressive segregation, adaptation and speciation. Heredity (Edinb) 1999 Oct;83(Pt 4):363–372. doi: 10.1038/sj.hdy.6886170. [DOI] [PubMed] [Google Scholar]
- Rieseberg L. H., Baird S. J., Gardner K. A. Hybridization, introgression, and linkage evolution. Plant Mol Biol. 2000 Jan;42(1):205–224. [PubMed] [Google Scholar]
- Rieseberg L. H., Beckstrom-Sternberg S., Doan K. Helianthus annuus ssp. texanus has chloroplast DNA and nuclear ribosomal RNA genes of Helianthus debilis ssp. cucumerifolius. Proc Natl Acad Sci U S A. 1990 Jan;87(2):593–597. doi: 10.1073/pnas.87.2.593. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Soltis DE, Soltis PS. Polyploidy: recurrent formation and genome evolution. Trends Ecol Evol. 1999 Sep;14(9):348–352. doi: 10.1016/s0169-5347(99)01638-9. [DOI] [PubMed] [Google Scholar]
- Soltis P. S., Soltis D. E. The role of genetic and genomic attributes in the success of polyploids. Proc Natl Acad Sci U S A. 2000 Jun 20;97(13):7051–7057. doi: 10.1073/pnas.97.13.7051. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wolff K., Peters-van Rijn J. Rapid detection of genetic variability in chrysanthemum (Dendranthema grandiflora Tzvelev) using random primers. Heredity (Edinb) 1993 Oct;71(Pt 4):335–341. doi: 10.1038/hdy.1993.147. [DOI] [PubMed] [Google Scholar]