Advanced

Evolution and systematics of polyploid Nigritella (Orchidaceae)

Hedrén, Mikael LU ; Lorenz, Richard; Teppner, Herwig; Dolinar, Branko; Giotta, Cesario; Griebl, Norbert; Hansson, Sven; Heidtke, Ulrich; Klein, Erich and Perazza, Giorgio, et al. (2018) In Nordic Journal of Botany 36(3).
Abstract

Members of the orchid genus Nigritella are widespread in European mountains, but species circumscriptions and evolutionary patterns in the genus are subjects to conflicting opinions. We analyzed a representative material of Nigritella for differentiation at nuclear and plastid marker loci. In agreement with predictions from embryological studies, diploid members of Nigritella are sexual and mostly out-crossing, whereas triploid, tetraploid and pentaploid members are apomicts. The diploid taxa were poorly differentiated in the investigated molecular markers, except for the western N. gabasiana, which was separated in plastid haplotypes. Polyploid Nigritella aggregate into three groups and within each of these groups apomictic polyploids... (More)

Members of the orchid genus Nigritella are widespread in European mountains, but species circumscriptions and evolutionary patterns in the genus are subjects to conflicting opinions. We analyzed a representative material of Nigritella for differentiation at nuclear and plastid marker loci. In agreement with predictions from embryological studies, diploid members of Nigritella are sexual and mostly out-crossing, whereas triploid, tetraploid and pentaploid members are apomicts. The diploid taxa were poorly differentiated in the investigated molecular markers, except for the western N. gabasiana, which was separated in plastid haplotypes. Polyploid Nigritella aggregate into three groups and within each of these groups apomictic polyploids have given rise to new species. Within the N. nigra group, the tetraploid N. nigra subsp. austriaca is somewhat differentiated from the triploid subsp. nigra at nuclear as well as plastid loci. Fusion of an unreduced egg cell from subsp. nigra with a haploid microgamete from Gymnadenia conopsea gave rise to Gymnigritella runei. Within the N. widderi group, N. archiducis-joannis is poorly separated from N. widderi in molecular markers, and the pentaploid N. buschmanniae has evolved by fusion of an unreduced egg cell from N. widderi with a haploid microgamete from a diploid Nigritella. Within the N. miniata group, N. stiriaca is somewhat differentiated from N. miniata at nuclear loci, but no other segregates of N. miniata are supported at species level. Polyploid Nigritella species accumulate genetic diversity by somatic mutations. In the widespread N. nigra subsp. austriaca and N. miniata this diversity is correlated to geography. Although some polyploids may be of recent origins, each polyploid contain genetic markers no longer encountered in diploid members of the genus. According to plastid marker data, Nigritella and Gymnadenia may constitute monophyletic sister genera.

(Less)
Please use this url to cite or link to this publication:
author
, et al. (More)
(Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
embryology, genetic diversity, geographic variation, Nigritella, Orchidaceae, phytogeography, plastid DNA, postglacial migration
in
Nordic Journal of Botany
volume
36
issue
3
publisher
Board of the Nordic Journal of Botany
external identifiers
  • scopus:85044577374
ISSN
0107-055X
DOI
10.1111/njb.01539
language
English
LU publication?
yes
id
0cd600ae-68a9-464d-8681-96c28dc9dae8
date added to LUP
2018-04-11 13:04:11
date last changed
2019-08-14 04:14:13
@article{0cd600ae-68a9-464d-8681-96c28dc9dae8,
  abstract     = {<p>Members of the orchid genus Nigritella are widespread in European mountains, but species circumscriptions and evolutionary patterns in the genus are subjects to conflicting opinions. We analyzed a representative material of Nigritella for differentiation at nuclear and plastid marker loci. In agreement with predictions from embryological studies, diploid members of Nigritella are sexual and mostly out-crossing, whereas triploid, tetraploid and pentaploid members are apomicts. The diploid taxa were poorly differentiated in the investigated molecular markers, except for the western N. gabasiana, which was separated in plastid haplotypes. Polyploid Nigritella aggregate into three groups and within each of these groups apomictic polyploids have given rise to new species. Within the N. nigra group, the tetraploid N. nigra subsp. austriaca is somewhat differentiated from the triploid subsp. nigra at nuclear as well as plastid loci. Fusion of an unreduced egg cell from subsp. nigra with a haploid microgamete from Gymnadenia conopsea gave rise to Gymnigritella runei. Within the N. widderi group, N. archiducis-joannis is poorly separated from N. widderi in molecular markers, and the pentaploid N. buschmanniae has evolved by fusion of an unreduced egg cell from N. widderi with a haploid microgamete from a diploid Nigritella. Within the N. miniata group, N. stiriaca is somewhat differentiated from N. miniata at nuclear loci, but no other segregates of N. miniata are supported at species level. Polyploid Nigritella species accumulate genetic diversity by somatic mutations. In the widespread N. nigra subsp. austriaca and N. miniata this diversity is correlated to geography. Although some polyploids may be of recent origins, each polyploid contain genetic markers no longer encountered in diploid members of the genus. According to plastid marker data, Nigritella and Gymnadenia may constitute monophyletic sister genera.</p>},
  articleno    = {e01539},
  author       = {Hedrén, Mikael and Lorenz, Richard and Teppner, Herwig and Dolinar, Branko and Giotta, Cesario and Griebl, Norbert and Hansson, Sven and Heidtke, Ulrich and Klein, Erich and Perazza, Giorgio and Ståhlberg, David and Surina, Boštjan},
  issn         = {0107-055X},
  keyword      = {embryology,genetic diversity,geographic variation,Nigritella,Orchidaceae,phytogeography,plastid DNA,postglacial migration},
  language     = {eng},
  month        = {03},
  number       = {3},
  publisher    = {Board of the Nordic Journal of Botany},
  series       = {Nordic Journal of Botany},
  title        = {Evolution and systematics of polyploid Nigritella (Orchidaceae)},
  url          = {http://dx.doi.org/10.1111/njb.01539},
  volume       = {36},
  year         = {2018},
}