ISSN 10227954, Russian Journal of Genetics, 2013, Vol. 49, No. 11, pp. 1175–1182. © Pleiades Publishing, Inc., 2013.
Original Russian Text © E.N. Savelyeva, K.V. Boris, E.Z. Kochieva, A.M. Kudryavtsev, 2013, published in Genetika, 2013, Vol. 49, No. 11, pp. 1345–1352.
Genus Malus (apple tree), as well as other fruit cul
tures of economical significance (
Pyrus, Cydonia, Aro
nia, Chaenomeles, Crateagus
), belongs to
of the family Rosaceae .
According to different current classifications, the
includes 8–78 growing wild plants .
Despite the quite long period of domestication (about
4000 years ago) and the significance of the apple tree
as important fruit agriculture, questions still remain
regarding the species composition and phylogeny of
The majority of current classifications of the genus
have been traditionally based on morphological
traits, such as the structure of vegetative and generative
organs, as well as on geographical distribution . The
polyploidy of diverse members from this genus, the
capacity for intraspecies hybridization, and the high
level of intraspecies polymorphism strongly compli
cate the classification and cause disagreement on the
subject of the species composition of the genus.
In terms of the complexity of using only morpho
logical traits, methods of genomic molecular analysis
are being increasingly actively used for the phylogeny
and taxonomy of the genus
The ITS15.8SITS2 region at a ribosomal operon
is currently used to establish the taxonomic composi
tion of many families and genera, to verify the phylo
genetic relationships, and to identify samples for many
plant genera [4–6]. The ITS15.8SITS2 sequence
has already been used in a number of studies to analyze
the Rosaceae family, e.g., in members of the
 genera, as well as species of the genus
[2, 9, 10].
The Vavilov Institute of the Plant Industry, Russian
Academy of Agricultural Sciences, contains a unique
collection of members of the
genus from differ
ent geographical regions of Russia, as well as from the
origin of the apple tree, the Middle East. Earlier, the
molecular–genetic analysis of this collection has not
been performed. Therefore, it is of interest to carry out
a molecular–genetic characterization of samples,
including those collected for analysis for the first time,
, in order
to determine the taxonomic position of the sample and
to evaluate the intraspecies and interspecies polymor
phism levels of the genome. The ITS15.8S region of
was used for analysis.
A total of 41 samples of 39 species of
belong to different series of sections
catomalus (Gymnomeles), Sorbomalus, Chloromeles,
(Table 1), were analyzed.
JQ041777 DNA were used as the exter
nal sequence group extracted according to the tech
nique proposed by Puchooa .
During the study, the ITS1 transcribed spacer
region and 5.8S rRNA gene sequences were analyzed
and sequenced for a total of 41
samples. We used
universal sequences of primers proposed by White
(ITS4: TCCTC CGCTTATTGATATGC, ITS5:
As expected, the nucleotide sequence of the
5.8S gene was found to be conserved. The length of the
5.8S rRNA gene was found to be 165 bp for all ana
lyzed members of the apple tree genus; no substitu
tions were identified (Table 2).
Analysis of Sequences of ITS1 Internal Transcribed Spacer
and 5.8S Ribosome Gene of
E. N. Savelyeva
, K. V. Boris
, E. Z. Kochieva
, and A. M. Kudryavtsev
Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia
Bioengineering Center, Russian Academy of Sciences, Moscow, 117312 Russia
Received April 16, 2013
—The nucleotide sequence of the ITS15.8S ribosomal DNA spacer fragment was determined for
41 samples of the
species. The total length of compared sequences ranged from 389 to 392 bp. The
nucleotide sequence of the 5.8S gene within the genus was highly conserved. The level of polymorphism of
ITS1 region comprised 14%. Both species and groupspecific substitutions were identified. The analysis of
sequences revealed their full identity, which indicates the need to perform
more research with a larger number of samples of both species from other collections to clarify the taxonomic
status of the
species. The previous findings on the synonymy of species
M. mandshurica, M. pallasiana
were also confirmed.