Homoploid hybrid speciation in Doronicum L. (Asteraceae)? Morphological, karyological and molecular evidences

Abstract

The first unambiguous documentation of hybridism in the genus Doronicum (Senecioneae – Asteraceae) is reported. All our morphological, karyological and molecular data concur to indicate that Doronicum × minutilloi Peruzzi hybr. nov. (2n = 60) is a hybrid growing in Monti Aurunci (Central Italy), originated from the spontaneous crossing D. orientale Hoffm. (2n = 60) × D. columnae Ten. (2n = 60). This new hybrid shows a slightly higher morphological, karyotypic and ribotypic affinity with D. columnae, but shares a trnL-trnF IGS haplotype with D. orientale, and co-occurs with the latter species only; it has reduced fertility and a high potential for vegetative propagation through rhizome fragmentation. Our results led us to suspect in fieri homoploid hybrid speciation.

Keywords:

• Doronicum
• flora
• hybrids
• Italy
• ribotypes

Acknowledgements

The authors wish to thank Antonio Giordani (University of Pisa), who was an indispensable help in the laboratory, one anonymous reviewer and Clemens Pachschwöll (University of Vienna) for constructive criticisms and useful suggestions. Financial funding (EX60%) from University of Pisa is gratefully acknowledged.