RT journal article
T1 Big thistle eats the little thistle: does unidirectional introgressive hybridization endanger the conservation of Onopordum hinojense?
A1 Balao, Francisco
A1 Casimiro-Soriguer Camacho, Ramón
A1 Garcia Castaño, Juan Luis
A1 Terrab, Anass
A1 Talavera, Salvador
A2 Biología
AB Hybridization is known to have a creative role in plant evolution. However, it can also have negative effects on parental species. Onopordum is a large genus whose species frequently hybridize. In the Southwest Iberian Peninsula, the rare O. hinojense co-occurs with the widely distributed O. nervosum, and hybrids between these two taxa have been described as O. × onubense.    In this study we determine the extinction risk in a hybrid zone, both for hybrids and parentals, using analyses of morphological and cytogenetic traits as well as genetic markers and demographic models. To investigate the introgression process we used amplified fragment length polymorphism (AFLP) markers, Bayesian analyses and genome scan methods.    Morphology, genome size and molecular markers confirmed homoploid hybridization and also indicated unidirectional backcrossing of F1 hybrids with O. nervosum, which is likely to swamp O. hinojense, the parental with lower pollen size and a very low fruit set (8%). Genome scan methods revealed several loci significantly deviating from neutrality. Finally, our demographic modeling indicated that the higher fitness of O. nervosum threats the survival of O. hinojense by demographic swamping.    Our study provides strong new evidence for a scenario of rapid extinction by unidirectional introgression and demographic swamping. The multifaceted approach used here sheds new light on the role of introgression in plant extinctions.
PB Wiley
SN 1469-8137
YR 2015
FD 2015
LK http://hdl.handle.net/10498/30240
UL http://hdl.handle.net/10498/30240
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 21-sep-2026