Az Annals of Botany című folyóirat elfogadta
közlésre a 'Molecular phylogeny and evolutionary history of the
Eurasiatic orchid genus Himantoglossum s.l. (Orchidaceae)' című cikkünket
(szerzők: Sramkó G. – Molnár V. A. - Hawkins J. A. -
Bateman R. B.).
Abstract
• Background and Aims
All putative species of the charismatic orchid genus Himantoglossum s.l. were
sampled across its geographical range in order to better understand the
evolutionary relationships among species of particular conservation concern.
• Methods A large subsample of the 153 populations studied contributed to an
initial survey of nrITS ribotypes. Smaller subsets were then sequenced for four
plastid regions and the first intron of the low-copy nuclear gene LEAFY. Rooted
using Steveniella as outgroup, phylogenetic trees were generated using
parsimony and Bayesian methods from each of the three datasets, supplemented
with a ribotype network.
• Key results The resulting trees collectively determined the order of
branching of the early divergent taxa as H. comperianum > H. robertianum
group > H. formosum, events that also involved significant morphological
divergence. Relaxed molecular clock dating suggests that these divergences
preceded the Pleistocene glaciations-the origin of the H. robertianum group may
have coincided with the Messinian salinity crisis-and occurred in Asia Minor
and/or the Caucasus. Among more controversial taxa of the H. hircinum-jankae
clade, which are only subtly morphologically divergent, topological resolution
is poorer and topological incongruence between datasets is consequently
greater.
• Conclusions Plastid sequence divergence is broadly consistent with prior,
morphologically circumscribed taxa and indicates a division between H.
hircinum-adriaticum to the west of the Carpathians and H. jankae-caprinum (plus
local endemics) to the east-a distinction also suggested by ITS ribotypes.
LEAFY phylogenies are less congruent with prior taxonomic arrangements and
include one likely example of paralogy. Himantoglossum metlescisianum fully
merits its IUCN Endangered status. Potentially significant genetic variation
was detected within Steveniella satyrioides, H. robertianum and H. hircinum.
However, confident circumscription of the more derived species of
Himantoglossum s.s., including local endemics of hybrid origin, must await
future morphometric and population-genetic analyses.
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