Marked hybridization and introgression in Ophrys sect. Pseudophrys in the western Iberian Peninsula

Abstract

Because postzygotic barriers are weak, leakage in this highly specialized orchid-pollinator system contributes to hybridization and introgression. These leakages may have occurred during periods of past climate change, promoting homogenization and the potential for generations of new biodiversity via production of novel genotypes/phenotypes interacting with pollinators.

Integrating restriction site-associated DNA sequencing (RAD-seq) with morphological cladistic analysis clarifies evolutionary relationships among major species groups of bee orchids

“…), Ophrys has also become a catalyst for occasionally intense debates, both evolutionary and taxonomic, that focus especially on the significance and fidelity of the plant–pollinator relationship (‘ethology’ sensu Bateman et al , 2011 ) and the degree of relevance to the circumscription of species within the group (cf. Bateman et al , 2011 ; Vereecken et al , 2011 ; Bateman, 2012 ; Schlüter and Johnson, 2013; Paulus, 2015 ; Véla et al , 2015 ; Cotrim et al , 2016 ). However, in order to pursue well-informed discussions on these topics, it is first necessary to have at our disposal an equally well-founded phylogeny that reveals the evolutionary relationships of the major groups within the genus, and to use that phylogeny to infer the sequence in which the many putative adaptations of the Ophrys flower were acquired by each of those major clades.…”

Ophrys fuscaandOphrys dyris(Orchidaceae) – constancy of tetraploidy amongst populations in Central Portugal

“…), which seem to indicate O. lutea (section Ophrys) as one of the parents. In addition, Cotrim et al (2016), supported by plastid haplotypes, reported introgressed individuals and hybridising populations between fusca-lutea, bearing out the tight relationship between these species previously pointed out by Soliva et al (2001).…”

“…Ophrys dyris Maire and Ophrys fusca Link are one pair of species found in sympatry and offering opportunity for the study of hybridisation in the context of a specialised orchid-pollinator system. These two species are respectively included in the groups omegaifera and fusca of section Pseudophrys Godfery (Orchidaceae) and are closely related (Bernardos et al, 2005;Cotrim et al, 2016;Devey et al, 2008). Despite the different approaches and reported relationships pointed out below, we refer these taxonomic entities as separate species, as our preliminary morphological analysis seem to maintain the segregration between specimens presenting trait expression of the diagnostic characters in the mean values of its description range.…”

“…Ophrys dyris and O. fusca have similar morphological characters, and careful inspection is needed for field identification (Figure 1), particularly as intermediate individuals are known, some of which have been characterised as hybrids using co-dominant molecular marker data (Cotrim et al, 2016).In 1981 the name O. ×brigittae H.Baumann was used to refer to the hybrids between Ophrys dyris and Ophrys fusca.…”

“…Ophrys fusca is known to exist at diploid (2n = 2x = 36) and tetraploid (2n = 4x = 72) levels (Greilhuber and Ehrendorfer, 1975), whereas tetraploid and pentaploid (2n = 4x = 90) cytotypes of O. dyris have been described. Greilhuber and Ehrendorfer (1975) Cotrim et al (2009Cotrim et al ( , 2016 inferred that specimens from the western Iberian Peninsula with four alleles per individual for some microsatellite loci were tetraploid. Considering O. dyris, following an early report of tetraploid plants (Kullenberg 1961), Bernardos et al (2003), later cited by Aedo and Herrero (2005) and Amich et al (2007), reported counts of 2n = 4x =72 and 2n = 5x = 90.…”