Patterns of hybridization in a multispecies hybrid zone in theRanunculus cantoniensiscomplex (Ranunculaceae)

Abstract

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 Ranunculus cantoniensis complex over a microgeographical area in south‐western China. Sequence information from maternally inherited plastid DNA (trnQ‐rps16 and rpL32‐trnL) 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.

Peer Review #1 of "Evidence for continual hybridization rather than hybrid speciation between Ligularia duciformis and L. paradoxa (Asteraceae) (v0.1)"

“…Backcrossing has also been suggested previously to cause frequent gene flow between Ligularia species, giving rise to complex relationships between them (Yu et al, 2011). In our results, some individuals had unique haplotypes; such variants might be caused by hybridization between parents containing different ITS sequences (Baldwin et al, 1995;Sang et al, 1995;Li et al, 2014) or independent evolution of haplotypes through mutation exceeding the rate of concerted evolution or pseudogenization among ITS copies (Feliner & Rosselló, 2007;Kosnar et al, 2012).…”

Evidence for continual hybridization rather than hybrid speciation betweenLigularia duciformisandL. paradoxa(Asteraceae)

“…Backcrossing has also been suggested previously to cause frequent gene flow between Ligularia species, giving rise to complex relationships between them ( Yu, Kuroda & Gong, 2011 ). In our results, some individuals had unique haplotypes; such variants might be caused by hybridization between parents containing different ITS sequences ( Baldwin et al, 1995 ; Sang, Crawford & Stuessy, 1995 ; Li et al, 2014 ) or independent evolution of haplotypes through mutation exceeding the rate of concerted evolution or pseudogenization among ITS copies ( Feliner & Rosselló, 2007 ; Kosnar et al, 2012 ).…”

The cost of self‐promotion: ecological and demographic implications of the mentor effect in natural plant populations

“…Here, we measure selfing rate under natural and experimentally manipulated environments to probe the underlying ecological conditions necessary for the mentor effect in native Taraxacum populations and address its consequences for fitness and population growth. We also test the hypothesis that the mentor effect is a form of reproductive interference, because it promotes inbreeding depression in self‐incompatible plants with high genetic load (Stephenson et al ., 2000; Michalski & Durka, 2007; Li et al ., 2014).…”