Hybridization drives speciation in Gagea (Liliaceae)

Abstract

Hybridization seems to play an important role in speciation of Gagea Salisb., a genus which is characterised by polyploid taxa lines and in which diploids (2n = 24) appear only to be common in basal sections. Hybrid detection was applied utilising direct and cloning nrDNA ITS data (ITS1, 5.8S rDNA, ITS2) combined with neighbour and ribotype networks and discussed in connection with previously published cpDNA, morphological and karyological data of the authors. We have evidence of the hybrid origin of taxa within the section Gagea (G. pomeranica, G.megapolitana) and the monophyletic clade of sections Didymobulbos and Fistulosae (G. microfistulosa, G. polidorii, G. cf. bohemica). Morphologically and karyologically differentiated Gageamegapolitana and G. pomeranica, adapted to synanthropic habitats, represent both hybrids of G. pratensis × G. lutea. Gagea microfistulosa represents a hybrid of G. villosa × G. fragifera; Gagea polidorii could represent the reverse hybrid. G. glacialis is also closely related to the latter complex.