Patterns of hybridization in a multispecies hybrid zone in the R anunculus cantoniensis complex ( R anunculaceae)

Simultaneous hybridizations among three or more parental taxa occur in nature, but these have rarely been analysed. The present study investigates the natural hybridization of diploid members of the R anunculus cantoniensis complex over a microgeographical area in south‐western C hina. Sequence information from maternally inherited plastid DNA ( trn Q ‐rps16 and rp L 32‐trn L ) and biparentally inherited nuclear ribosomal DNA was used to identify hybrids, and these were further confirmed by a dramatic reduction in pollen viability. The populations from the contact zone contained individuals that had more than two nuclear ribosomal internal transcribed spacer ( nrITS ) types; in addition, a network analysis revealed the presence of hard conflicts between the nuclear and plastid DNA data. These results prove that R . trigonus and R . silerifolius var. dolicanthus have relatively little reproductive isolation from each other, leading to a high gene flow rate in contact populations. The four investigated species can hybridize with each other in this contact zone, forming seven hybrid types. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society , 2014, 174 , 227–239.