Evidence for bidirectional hybridization between Gymnadenia and Nigritella

Research output: Contribution to journalArticle

Abstract

Despite morphological divergence, the two orchid genera Gymnadenia and
Nigritella are closely related and hybrids are often encountered at places where
members of the two genera grow together. On basis of pollination studies, it has
been suggested that members of Nigritella should have served as pollen parent to
these hybrids. Hybridization does not go beyond primary hybrid formation, but
one of the hybrids, Gymnigritella runei, is recognized as a separate species since
the hybrid genotype is maintained by apomixis and it is reproducing
independently of the parents. Surprisingly, a recent molecular analysis of G. runei
demonstrated that this hybrid evolved by the merger of an egg cell from Nigritella
and a microgamete from Gymnadenia, contrary to what has been predicted from
pollination studies. Here, we conducted an extended study in which we analyzed
two additional hybrid combinations known from the Alps and which each has
originated repeatedly at different sites: G. conopsea × N. rhellicani, and
G. odoratissima × N. rhellicani. We show that each hybrid combination has
originated alternatively from Nigritella and Gymnadenia as egg parent. Our
results call for renewed studies on the pollination biology of Nigritella and
Gymnadenia, in particular on the movement of insects between plants of the
different genera and their potential function as pollen vectors.

Details

Authors
Organisations
External organisations
  • Arbeitskreis Heimische Orchideen Baden-Württemberg
  • Swedish Board of Agriculture
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Botany
Original languageEnglish
Pages (from-to)43-60
JournalJournal Europäischer Orchideen
Volume50
Issue number1
Publication statusPublished - 2018
Publication categoryResearch
Peer-reviewedNo