Karyological studies on Orchidaceae. Tribe Ophrydeae, subtribe Serapiadinae

The relationships between Dactylorhiza romana and D. saccifera from southern Italy were analysed. These two species, both with 2n = 2x = 40 chromosomes and belonging to different sections of the genus, were distinguishable on the basis of karyotype structure and heterochromatin amounts and distribution. Their C‐banded karyotypes differed considerably. D. saccifera showed most chromosomes with banded regions in the short arms, whereas in D. romana the bands were located mostly at telomeric regions of longer arms. Several individuals of D. romana had one or two very large heterochromatic supernumerary chromosomes. Based on evidence resulting from karyotype structure and heterochromatin distribution in the two species and on the genetic distances derived from the comparison of ITS sequences, it is suggested that D. romana represents a primitive form with respect to D. saccifera and is a possible intermediate step in the evolution of the genus Dactylorhiza from the 42‐chromosome Orchis group. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 138, 85–91.

Section: Discussionmentioning

confidence: 97%

“…The karyotype structure of the genus is known from only three taxa, namely D. maculata ssp. meyeri (Vöth & Greilhuber, 1980), D. sambucina (Cauwet‐Marc & Balayer, 1984) and D. insularis (D’Emerico et al , 1992).…”

Section: Introductionmentioning

confidence: 99%

Karyotype structure, supernumerary chromosomes and heterochromatin distribution suggest a pathway of karyotype evolution inDactylorhiza(Orchidaceae)

D’Emerico

Cozzolino²,

Pellegrino

et al. 2002

“…In fact, there is a considerable differentiation between the two genera in karyotype structure and C‐banded heterochromatin. Therefore, the genera Ophrys and Serapias appear to be karyotypically strongly differentiated (D’Emerico et al ., 1990, 2000; D’Emerico, Bianco & Medagli, 1992). It is interesting to note that ITS data support the smaller degree of differentiation in Serapias species (Bateman et al ., 2003) that we have observed karyologically (D’Emerico et al ., 2000, and references therein).…”

Section: Discussionmentioning

confidence: 99%

Karyomorphology, heterochromatin patterns and evolution in the genus Ophrys (Orchidaceae)

D’Emerico

Pignone²,

Bartolo

et al. 2005

Karyotype structures and heterochromatin distribution in representative taxa of the genus Ophrys are compared, based on Feulgen-stained and banded somatic metaphase chromosomes. The karyotypes of Ophrys iricolor , O. lupercalis , O. caesiella , O. lutea , O. lunulata , O. x. tardans , O. apifera , O. praecox , O. lacaitae and O. insectifera are described for the first time. The karyological analyses indicate the relationships among the species with respect to asymmetry indices and heterochromatin content. Chromosomal differences have been helpful in clarifying the taxonomic position of Ophrys species that do not have clear affinities. The representative species of Araniferae , Fuciflorae and Ophrys sections exhibited the most asymmetrical karyotypes, while chromosome complements of the O. fusca-O. lutea group, of O. tenthredinifera and of O. bombyliflora proved to be less asymmetrical. Weakly heterochromatic chromosomes, with heterochromatin present mostly in thin centromeric bands, characterizeOphrys C-banded karyotypes. Chromomycin A 3 (CMA) staining revealed that the analysed species exhibit a weak pattern of CMA + bands at centromeric, intercalary or telomeric regions. No DAPI bright blocks were observed. The significance of the karyological data is discussed with regard to the relationships between the analysed species.

“…Chromosomally, Himantoglossum s.s. and Barlia have recently been carefully examined and shown to have the 36 chromosomes expected of members of the large 2 n = 36 clade identified by Pridgeon et al . (1997), though H. hircinum possesses an additional B‐chromosome (Carpineri & Rossi, 1987; D’Emerico, Bianco & Medagli, 1992). Steveniella has been reported to have the improbable karyotype of 2 n = 38 by Sundermann & von der Bank (1977), but this assertion may simply reflect the possible presence of another B‐chromosome analogous to that of H. hircinum .…”

Section: Relationships Within the Major Cladesmentioning

confidence: 99%

Molecular phylogenetics and evolution of Orchidinae and selected Habenariinae (Orchidaceae)

Bateman

Hollingsworth

Preston

et al. 2003

321

422

Internal transcribed spacer (ITS nuclear rDNA) data have been obtained from 190 terrestrial orchid species, encompassing all genera and the great majority of the widely recognized species of Orchidinae, a heterogeneous selection of species of Habenariinae, and single species of Satyriinae and Disinae (the latter serving as outgroup). The resulting parsimony‐based phylogeny reveals 12 well‐resolved clades within the Orchidinae, based on Anacamptis s.l., Serapias, Ophrys, Steveniella–Himantoglossum s.l. (including ‘Comperia’ and ‘Barlia’, most species being 2n = 36), Neotinea s.l., Traunsteinera–Chamorchis, Orchis s.s., Pseudorchis–Amerorchis–Galearis–Neolindleya–Platanthera s.l. (most 2n = 42), Dactylorhiza s.l., Gymnadenia s.l. (most 2n = 40, 80), Ponerorchis s.l.–Hemipilia s.l.–Amitostigma–Neottianthe, and Brachycorythis (most 2n = 42). Relationships are less clearly resolved among these 12 clades, as are those within Habenariinae; the subtribe appears either weakly supported as monophyletic or as paraphyletic under maximum parsimony, and the species‐rich genus Habenaria is clearly highly polyphyletic. The triphyly of Orchis as previously delimited is confirmed, and the improved sampling allows further generic transfers to Anacamptis s.l. and Neotinea s.l. In addition, justifications are given for: (1) establishing Steveniella as the basally divergent member of an appreciably expanded Himantoglossum that incorporates the former genera ‘Barlia’ and ‘Comperia’, (2) reuniting ‘Piperia’ with a broadly defined Platanthera as section Piperia, necessitating ten new combinations, (3) broadening Ponerorchis to include Chusua, and Hemipilia to include single ‘orphan’ species of Ponerorchis and Habenaria, and (4) recognizing ‘Gymnadenia’camtschatica as the monotypic Neolindleya camtschatica within the Pseudorchis∼Platanthera clade. Few further generic transfers are likely in Orchidinae s.s., but they are anticipated among habenariid genera, on acquisition of additional morphological and molecular evidence; one probable outcome is expansion of Herminium. Species‐level relationships are also satisfactorily resolved within most of the major clades of Orchidinae, with the notable exceptions of Serapias, the derived sections of Ophrys, Himantoglossum s.s., some sections within Dactylorhiza, the former genus ‘Nigritella’ (now tentatively placed within Gymnadenia s.l.), Hemipilia s.l., and possibly Ponerorchis s.s. Relationships among the 12 major clades broadly accord with bona fide records of intergeneric hybridization. Current evidence supports the recently recognized 2n = 36 clade; it also indicates a 2n = 40 clade that is further diagnosed by digitate root‐tubers, and is derived relative to the recently recognized clade of exclusively Asian genera (Ponerorchis s.l.–Hemipilia s.l.–Amitostigma–Neottianthe). This in turn appears derived relative to the Afro‐Asiatic Brachycorythis group; together, these two clades identify the plesiomorphic chromosome number as 2n = 42. If the African genus Stenogolottis is correctly placed as b...