Interspecific hybridization in the genus Hieracium (s. str.) – evidence for bidirectional gene flow and spontaneous allopolyploidization

0364321 - BÚ 2012 RIV AT eng J - Journal Article
Mráz, P. - Chrtek, Jindřich - Fehrer, Judith
Interspecific hybridization in the genus Hieracium (s. str.) – evidence for bidirectional gene flow and spontaneous allopolyploidization.
Plant Systematics and Evolution. Roč. 293, 1-4 (2011), s. 237-245. ISSN 0378-2697. E-ISSN 1615-6110
R&D Projects: GA ČR GAP506/10/1363
Institutional research plan: CEZ:AV0Z60050516
Keywords : additive polymorphism * hybridization * polyploidization
Subject RIV: EF - Botanics
Impact factor: 1.335, year: 2011

Well-documented cases of recent interspecific hybridization in Hieracium s. str. are very rare. We report combined evidence on recent hybridization between two diploid species, H. alpinum and H. transsilvanicum, based on additive patterns of nrDNA polymorphism (ITS), an intermediate position of hybrid plants in PCO analyses based on AFLP phenotypes, and additivity at one allozyme locus. Two hybrids were diploid while one was surprisingly tetraploid. This is the first record of spontaneous polyploidization following interspecific crossing in the genus. Allozyme data suggest the origin of this tetraploid via a triploid bridge with subsequent backcrossing to H. alpinum. All H. x krasani hybrids had the H. alpinum cpDNA haplotype while H. transsilvanicum served as a pollen donor. The hybrids occurred together with abundant H. alpinum plants; paternal H. transsilvanicum was missing. The direction of hybridization might be influenced by the frequency of parental taxa at the locality.
Permanent Link: http://hdl.handle.net/11104/0199836