ISSN 1022-7954, Russian Journal of Genetics, 2017, Vol. 53, No. 3, pp. 325–337. © Pleiades Publishing, Inc., 2017.
Original Russian Text © E.G. Filippov, E.V. Andronova, 2017, published in Genetika, 2017, Vol. 53, No. 3, pp. 310–323.
Genetic Structure of Populations and Natural Hybridization
between Dactylorhiza salina and D. incarnata (Orchidaceae)
E. G. Filippov
* and E. V. Andronova
Botanical Garden, Ural Branch, Russian Academy of Sciences, Yekaterinburg, 620144 Russia
Komarov Botanical Institute, Russian Academy of Sciences, St. Petersburg, 197376 Russia
Received March 28, 2016
Abstract⎯The results of studying the polymorphism and genetic structure of populations of D. salina and
D. incarnata growing in Zabaykalsky krai and Buryatia are represented according to the data of allozyme anal-
ysis of eight genetic loci (PGI, NADHD, SKDH, GDH, PGM, DIA, ADH, and IDH). The specificity of the
allelic structure of loci SKDH, PGM, and IDH is established, for which D. salina and D. incarnata reliably dif-
fer from each other. It is shown that interspecies introgressive hybrid complexes with different genetic struc-
tures were formed in Transbaikalia. Places of mass growth of D. incarnata were observed to have single plants
of D. salina, the interspecies hybrids of the first and subsequent generations. Places of mass growth of
D. salina were observed to contain only the hybrids that are not hybrids of the first generation. They were het-
erozygous not for three loci with differentiating alleles of both parents, SKDH, PGM, and IDH, but for only
one of them. The degree of genetic differentiation among five populations of D. salina was on average 7.5%
and that of D. incarnata was 7.1%, which in accordance with Wright’s estimation relates to mean values. The
average value of F
for all studied populations of the two related species of the genus Dactylorhiza was 0.478,
indicating a very high degree of genetic differentiation between D. salina and D. incarnata growing in Trans-
baikalia. The greatest differences between the species are for the allelic structure of loci SKDH, PGM, and
was equal to 0.705, 0.976, and 0.762, respectively). Analysis of molecular variance (AMOVA)
showed that populations of D. salina and D. incarnata in the zone where their ranges in Zabaykalsky krai and
Buryatya overlap have essential differences both for the variation of alleles frequencies of eight loci (71%,
d.f. = 9) and for the variability of genotypes (61%, d.f. = 9). Despite the fact that D. salina and D. incarnata
explicitly share a gene flow as a result of interspecies hybridization, the genetic differentiation of populations
of these related species remains at a high level.
Keywords: Dactylorhiza salina, D. incarnata, allozyme analysis, interspecies introgressive hybrid complexes,
According to L.V. Aver’yanov, Dactylorhiza salina
(Turcz. ex Lindl.) Soó and D. incarnata (L.) Soó
belong to subsection Dactylorhiza of the genus Dacty-
lorhiza. This subsection includes 26 species growing
mainly in Eurasia; in Russia, there are representatives
of six taxa [1, 2].
The range of D. salina is Caucasian-Asian, cover-
ing the Caucasus, Western and Eastern Siberia, the
Far East (Zeya-Bureya region), Central Asia, North
Mongolia, and East China . A typical sample of
D. salina was described from Transbaikalia.
The range of D. incarnata is Eurasian. Representa-
tives of this species grow in Europe (in the southern
part only in the mountains) from Great Britain and
Scandinavia to Central and Eastern Europe up to the
Urals. In Asia, the range covers Asia Minor, Iran, the
North Caucasus, Central Asia, Siberia, Mongolia, and
the northwestern part of China .
All species of orchids are rare plants. Establishment
of techniques for conservation of genetic diversity of
rare species requires information on polymorphism
and genetic structure of their populations. Quite a
major amount of work on the study of genetic charac-
teristics of representatives of the genus Dactylorhiza
was carried out mainly in Western Europe [4–11].
Samples from the territory of Russia, which accounts
for a large part of the range of D. incarnata, were
hardly used in these studies. Molecular-genetic stud-
ies carried out by foreign colleagues contain no infor-
mation about D. salina.
Transbaikalia is an area where the ranges of
D. salina and D. incarnata overlap (Fig. 1). According
to L.V. Aver’yanov, a vast area of introgression has