Diverse morphological and cytogenetic variation and differentiation of the two subspecies in <Emphasis Type="Italic">Aegilops geniculata</Emphasis> Roth,a wild relative of wheat

Aegilops geniculata Roth, a wild relative of wheat (2n = 4x = 28, genome UUMM), is distributed over the Mediterranean basin and nearby areas. The species consists of two subspecies, subsp. geniculata and subsp. gibberosa (Zhuk.) Hammer. The former is distributed over the whole species area and has been genetically analyzed, and the latter is endemic to Spain and North Africa and has not been genetically evaluated. In this study, to clarify the genetic variation and delineation of the two subspecies from a biosystematic viewpoint, morphological variation among 23 accessions of subsp. geniculata and three of subsp. gibberosa and chromosome pairing at meiosis and fertility in their intra- and inter-subspecific F₁ hybrids were examined. A principal component analysis based on the 11 spike characteristics clearly divided the 26 accessions into two groups representing the two subspecies. The inter-subspecific F₁ hybrids showed significantly lower frequencies of chromosome pairing, significantly higher frequencies of multivalents, and significantly lower fertilities relative to those of the intra-subspecific F₁ hybrids. It was concluded that wide-ranging cytogenetic variation is included in subsp. geniculata, that subsp. gibberosa, the intra-subspecific variation of which is small, is morphologically and cytogenetically differentiated from subsp. geniculata beyond the range of the intra-subspecific variation of subsp. geniculata, and that the two subspecies are effectively isolated reproductively by hybrid sterility. The results strongly suggested that western North Africa is one of the important diversity centers of Ae. geniculata, where two subspecies were differentiated in the past and grow together in the present.     

Polymorphism of <Emphasis Type="Italic">Got2</Emphasis> DNA sequences sheds light on <Emphasis Type="Italic">Aegilops tauschii</Emphasis> Coss. intraspecies divergence and origin of <Emphasis Type="Italic">Triticum aestivum</Emphasis> L.

DNA sequences of nuclear gene Got2 was studied in 60 accessions of Aegilops tauschii, 29 of subsp. tauschii and 31 of subsp. strangulata. It was found that Got2 allozyme polymorphism in Ae. tauschii is due to a single, unique, mutation which led to replacement of glutamic acid by isoleucine in residue 256 of the enzyme molecule, encoded by Got2. As revealed by Got2 DNA sequences variation, initially in its history Ae. tauschii was presented by subsp. strangulata, and among phylogenetic lineages of subsp. strangulata, the lineage “t-9¹s” (TauL3) is the most ancient, a relict one. Subspecies tauschii is relatively “young”. Initially it was presented by the lineage marked by combination of allozyme alleles Got2 ¹⁰⁵ and Acph1 ¹⁰⁰. In the past it inhabited the Continental area from Caucasia to Pakistan, but later on it was forced out by newly originated, now—a major lineage of subsp. tauschii, marked by Got2 ¹⁰⁰. This lineage extended the Continental area of the species up to Kirgizstan, but actually failed to penetrate into pre-Caspian area, occupied by subsp. strangulata. These results essentially differ from those obtained previously, using chloroplast DNA (cpDNA) sequences polymorphism. As revealed by cpDNA, the major, “usual”, subsp. strangulata (TauL2) is “younger” than subsp. tauschii, which resided on phylogenetic tree between relict lineage “t-9¹s”of subsp. strangulata—and major subsp. strangulata. But both cpDNA and Got2 DNA sequences indicate that the level of genetic variation in subsp. tauschii is much lower than in subsp. strangulata. According to Got2 DNA sequences variation, it was Ae. tauschii subsp. strangulata lineage “k-109″ which donated genome D to Triticum aestivum L. This lineage includes accessions: k-109 from South-Eastern Precaspian Azerbaijan; KU-2105, KU-2159 from Western Precaspian Iran; KU-2080 from Eastern Precaspian Iran.     

Remarks on genetic diversity and relationship of <Emphasis Type="Italic">Punica protopunica</Emphasis> and <Emphasis Type="Italic">P. granatum</Emphasis> assessed by molecular analyses

Here, two Punica species, viz., P. protopunica Balf. fil., reported as native to Socotra, and P. granatum L., were compared for the first time. Analysis of one P. protopunica and eleven P. granatum accessions was performed using three molecular markers, i.e., sequence related amplified polymorphism (SRAP), target region amplification polymorphism (TRAP), and intron targeted amplified polymorphism (ITAP), along with analysis of pgWD40 sequences, a gene involved in anthocyanin biosynthesis. All markers revealed the relationship between the two species and placed them at 33% similarity. SRAP, TRAP, and ITAP generated a total of 299, 260, and 160 bands, respectively. Of these, 78, 74, and 41 bands were specific for P. protopunica, and 92, 85, and 57 bands, respectively, were shared between both species. Sequence analysis of pgWD40~870 bp amplicons exhibited 100% identity among P. granatum accessions and 98% identity to that of P. protopunica. Phylogenetic analysis of WD40 sequences from monocot and dicot species, including both Punica species confirmed the relation between P. protopunica and P. granatum, supporting earlier reports that P. protopunica could be an ancestral species of P. granatum. Furthermore, the genetic diversity among and within P. granatum accessions from Egypt (3), Mexico (5), and Yemen (3) was assessed. Molecular marker-based relationships among region-bulked accessions was approximately the same (~90% similarity), whereas the degree of genetic variation was altered within each region. Specific bands (alleles) for accessions of each region along with those shared among them were identified. Thus, these bands could be used for pomegranate genotyping and breeding programs.     

Diversity analysis and evaluation of wild <Emphasis Type="Italic">Abelmoschus</Emphasis> species for agro-morphological traits and major biotic stresses under the north western agro-climatic condition of India

The wild species in general is considered to be the reservoir of genes especially for biotic and abiotic stresses. In okra, the predominant biotic stresses are yellow vein mosaic disease (YVMD), shoot and fruit borer and leaf hopper. Sixty eight (68) accessions belonging to four wild Abelmoschus species [Abelmoschus caillei (A. Chev.) Stevels, Abelmoschus manihot (L.) Medik., Abelmoschus moschatus (L.) Medik. and Abelmoschus tuberculatus Pal et Singh] and eight okra varieties were characterized and evaluated for phenological characters including biotic stresses under natural epiphytotic condition. The wild species examined consisted of 18 accessions (16 exotic and 2 indigenous) of A. caillei, 29 accessions of A. manihot, 16 accessions of A. moschatus and 5 accessions of A. tuberculatus. All the wild Abelmoschus species exhibited high diversity (as measured by Shannon Diversity Index) for 3 qualitative characters viz. intensity of stem colour, leaf shape, epicalyx shape, 13 quantitative characters and 3 biotic stress parameters. Among the wild species, A. caillei and A. tuberculatus showed maximum and minimum diversity for qualitative characters, respectively. There was significant variation for 19 out of 24 quantitative characters studied. Inter-species diversity pattern as estimated through Ward’s Minimum Variance Dendrogram and Principal Component Analysis revealed clear differentiation among the species with minimum overlapping indicating close association between geographical origins and clustering pattern. Intra-species diversity indicated role of specific adaptation in sub-clustering. Resistance to YVMD was found in accessions belonging to three wild species viz. A. caillei, A. manihot and A. moschatus while resistance to shoot and fruit borer and leaf hopper was found in accessions of all the four wild species. The resistant accessions can further be used for introgressing biotic stress resistance through pre-breeding into cultivated okra species.     

Polymorphism of gliadins in <Emphasis Type="Italic">Aegilops tauschii</Emphasis> Coss. local populations in two primary habitats in Dagestan

Polymorphism of gliadins was investigated in Aegilops tauschii from primary habitats “4”, near Hily, and “6”, near Rukel, in Dagestan, Russia 205 individual plants were analysed (53/50 and 54/48 plants of subsp. tauschii/subsp. strangulata from the habitats “4” and “6”, respectively) and 1/7 and 18/14 different haplotypes were found among the plants of subsp. tauschii/subsp. strangulata from the habitats “4” and “6”, respectively. No direct evidences of cross-pollination were pointed out, although gliadins electrophoretic phenotypes obtained allowed to suggest that it occur in Ae. tauschii with very low frequency. The data obtained revealed that during Ae. tauschii evolutionary history a local habitat could be populated many times by different phylogenetic lineages of the species. It was found that in Dagestan, at the very edge of the species area, several different lineages belonging to different subspecies could for a long time co-exist together in a local habit, and in such case a very high level of genetic variation in Ae. tauschii could be accumulated on a square of less than one hectare. The further studies of genetic variation in Ae. tauschii local populations, based on molecular genetic methods seems to be very prospective for understanding of peculiarities of the species evolution.     

Relationships among <Emphasis Type="Italic">Crataegus</Emphasis> accessions sampled from Hatay,Turkey, as assessed by fruit characteristics and RAPD

The genus Crataegus known as hawthorns, is the largest genus among the Maloideae, which comprises 265 species. Turkey is one of the genetic centers of Crataegus and there are more than 20 species found in Turkey. The fruits of Crataegus are used as food and have high flavonoid, vitamin C, glycoside, anthocyanidin, saponin, tannin, and antioxidant levels. In this study, we attempted to characterize 15 Crataegus accessions sampled from Hatay, located in Eastern Mediterranean region of Turkey. The accessions belonged to several species; C. aronia (L.) DC. var. aronia, C. aronia var. dentata Browicz, C. aronia var. minuta Browicz, C. monogyna Jacq. subsp. azarella (Griseb.) Franco, and C. orientalis Pall. ex M. Bieb. var. orientalis. Fruit characteristics of the accessions exhibited considerable variation. The multivariate, principle component and cluster analyses indicated that the accessions belonged to three groups: (1) C. aronia var. arona accessions; (2) C. aronia var. dentata accessions; and, (3) C. monogyna subsp. azarella and C. orientalis var. orientalis accessions. The principle component analysis results also revealed that the first three components explained 46, 21, and 14% of the variation, comprising a total of 81%. The fruit length and width, leaf area, and soluble solids contents were highly correlated characteristics for the first three components. The 19 RAPD primers generated a total of 107 bands, where 76 of these were polymorphic. The molecular data analyses by principle coordinate and clustering showed similar results to those of pomological characteristics. There were three groups, (1) C. aronia var. arona accessions; (2) C. aronia var. dentata accession; and, (3) C. monogyna subsp. azarella. C. orientalis var. orientalis accession grouped with C. aronia var. arona accessions. Therefore, it can be concluded that, overall, the diversity patterns of pomological and molecular data, generated by RAPD, for Crataegus are in good agreement and the accessions of C. aronia var. aronia, C. aronia var. minuta, C. monogyna subsp. azarella and C. orientalis var. orientalis accessions.     

Size homoplasy and mutational behavior of chloroplast simple sequence repeats (cpSSRs) inferred from intra- and interspecific variations in four chloroplast regions of diploid and polyploid <Emphasis Type="Italic">Triticum</Emphasis> and <Emphasis Type="Italic">Aegilops</Emphasis> species

Chloroplast simple sequence repeats (cpSSRs) are widely distributed in the chloroplast genomes of all plant species, and are frequently employed for genotypic and phylogenetic analysis. However, information on intra- and interspecies variation in cpSSRs is lacking. In this study, we sequenced four intergenic (non-coding) chloroplast DNA regions in 57 accessions of 12 tetraploid, and 16 accessions of 4 hexaploid species of Triticum and Aegilops. These sequence data added to our previous data for diploid species in the same chloroplast regions. Intra- and interspecific genetic variation was analyzed for a total of 189 accessions of 13 diploid, 12 tetraploid, and 4 hexaploid species of Triticum and Aegilops, such that all species were represented by multiple accessions. The data were used to infer phylogenetic relationships within and among Triticum and Aegilops species. Based on this robust phylogenetic tree, seven of eight cpSSR loci clearly exhibited “size homoplasy,” referring to the fact that cpSSRs of identical size and DNA sequence can arise even if the alleles are not descended from a common ancestor. These data indicate that cpSSRs should be used with caution in phylogenetic analyzes. Interestingly, as observed from several previous studies, our data also suggest that observed mutation rates may increase significantly when mononucleotide (homopolymer) repeat numbers reach or exceed 9 bp. In the present report, using this sequence data set involving cpSSRs, 81 unique haplotypes among 189 accessions were detected, and five tetraploid Triticum and Aegilops species were successfully identified and genotyped. Our results indicate that combinations of nucleotide substitutions, indels and SSRs of chloroplast nucleotide sequences are available for genotyping at the species accession level.     

Genetic diversity and relationships of wild and cultivated <Emphasis Type="Italic">Zanthoxylum</Emphasis> germplasms based on sequence-related amplified polymorphism (SRAP) markers

The genus Zanthoxylum, belonging to Rutaceae, has a long history of cultivation both for economic and chemical values in China. To effectively conserve and sustainably utilize this genus resource, a study on genetic diversity and relationships of Zanthoxylum germplasms was carried out by employing SRAP markers. We used 16 primer combinations to assess genetic variations and relationships among 175 accessions from eight cultivated provenances, including Shandong, Henan, Shanxi, Shaanxi, Gansu, Sichuan, Guizhou and Yunnan. A total of 145 clear repetitive and intense bands were yielded, and the percentage of polymorphic bands was 100 % for per primer combination, indicating a relatively high diversity among Zanthoxylum germplasms. From a geographic perspective, the highest genetic diversity level was observed within Guizhou provenance (N _a  = 1.97, Ne = 1.52, H = 0.31, I = 0.46) while Henan provenance had the lowest genetic diversity (N _a  = 1.68, Ne = 1.45, H = 0.25, I = 0.37). Based on AMOVA results, the abundant genetic variation was mainly caused by variation of intra-provenances (84.96 %), rather than among provenances (15.038 %). The results indicated low genetic differentiation (G _st  = 0.133) and high gene flow (N _m  = 3.2605) among provenances. The neighbor-joining tree revealed that the 175 accessions could be divided into four groups, and groupings indicated a divergence between the cultivated accessions of Zanthoxylum bungeanum Maxim. and Z. armatum DC. Moreover, three accessions of Z. piperitum DC. var. inerme without prickles introduced from Japan gathered one cluster. Cluster IV is composed of accessions of different geographical origin, including 11 wild species and 10 cultivated accessions of Z. bungeanum. The cluster analysis also reflected a relatively close relationship between the geographical origins and the classification of accessions in cluster I. Structure analysis indicated that collected Zanthoxylum accessions could be divided into two major groups. The information obtained from our research would benefit to make use of Zanthoxylum germplasms and assist the management of a Zanthoxylum germplasms collection.     

Genetic relationship of diploid wheat (<Emphasis Type="Italic">Triticum</Emphasis> spp.) species assessed by SSR markers

Genetic diversity of 139 accessions of diploid Triticum species including Triticum urartu, Triticum boeoticum and Triticum monococcum was studied using 11 SSR (simple sequence repeats) markers. A total of 111 alleles with an average of 10 alleles per locus were detected. The polymorphism information content (PIC) of each SSR marker ranged from 0.30 to 0.90 with an average value of 0.62. Among the three Triticum species T. urartu had the highest number of total alleles (Na?=?81), private alleles (Npa?=?15) and showed higher genetic diversity (Hex?=?0.58; PIC?=?0.54). The genotypes from Turkey exhibited the highest genetic diversity (PIC?=?0.6), while the least diversity was observed among 4 Georgian accessions (PIC?=?0.11). Cluster analysis was able to distinguish 139 wheat accessions at the species level. The highest genetic similarity (GS) was noted between T. boeticum and T. monococcum (GS?=?0.84), and the lowest between T. urartu and T. monococcum (GS?=?0.46). The grouping pattern of the PCoA analysis corresponded with cluster analysis. No significant differences were found in clustering of T. urartu and T. monococcum accessions with respect to their geographic regions, while within T. boeoticum species, accessions from Iran were somewhat associated with their geographical origin and clustered as a close and separate group. The results from our study demonstrated that SSR markers were good enough for further genetic diversity analysis in einkorn wheat species.     

Genetic diversity in populations of the medicinal plant <Emphasis Type="Italic">Leonurus cardiaca</Emphasis> L. revealed by inter-primer binding site (iPBS) markers

Motherwort (Leonurus cardiaca L.) is a medicinal plant indigenous to the Mediterranean regions in Europe and Asia. The objective of this study is to apply inter-primer binding site (iPBS) markers to assess the molecular variation and genetic relationships of 89 genotypes of motherwort to assist the genetic improvement of this species. The genotypes comprised 79 from Iran and 10 collected in Australia and 15 additional accessions of two related species (L. heterophyllus Sweet and L. sibiricus L.) collected in Australia, were also included. PCR of 7 iPBS primers (dominant markers) produced a total of 191 bands ranging from 180 to 4000 bp and the mean PIC for primers ranged from 0.2213 to 0.3206 with a mean value 0.2921. The mean expected heterozygosity (0.134), the mean unbiased expected heterozygosity (0.140) and Shannon’s information index (0.213) indicated a high level of inbreeding among the accessions tested. Ordination and cluster analysis showed that the genetic relationships among all accessions could be separated into three major groups—L. cardiaca, L. heterophyllus and L. sibiricus. However, among the 89 accessions of L. cardiaca, genotypes collected from the same geographic region tended to cluster together thus indicating greater genetic similarity. The Motherwort accessions originating in Iran are highly divergent and possess abundant genetic diversity and clearly provide a basis for selection and breeding. The iPBS PCR-based genome fingerprinting technology used in this study is low-cost and effective in differentiating accessions of motherwort and their related species.     

Natural diversity of inflorescence architecture traces cryptic domestication genes in barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.)

Many-grained mutants occurring spontaneously among their less well-endowed field mates may have appeared to early farmers as fortunate twists of fate foreboding wealth and abundance. In domesticated barley, the number of kernel rows in spike can be tripled by recessive mutant alleles at the Six-rowed spike 1 (vrs1) locus that abolish the suppression of lateral spikelet fertility. In another barley row-type, so called intermedium-spike (int), lateral floret size is often intermediate between six-and two-rowed types. Phenotypic and sequence analyses of our intermedium-spike collection revealed that other genes can increase the size of florets and even stimulate occasional grain setting in lateral spikelets. Here, we show that a complete six-rowed phenotype occurs in a diverse panel of intermedium-spike barley carrying wildtype Vrs1 in the presence of the Int-c.a allele of the intermedium spike-c (int-c) gene, previously considered only as a modifier of lateral spikelet fertility. Int-c.a-type alleles had arisen before domestication and are associated with the enlargement of lateral florets in wild barley, suggesting that natural selection/evolution acts towards reduced lateral floret size. Since Int-c.a cannot overcome the suppression of lateral florets in the genomic background of wild barleys, we infer the existence of other gene loci, at which novel alleles or allelic combinations were selected for after domestication, to increase grain number of barley independently of Vrs1.     

Allopatric distributions of tetraploid and hexaploid forms of Aegilops neglecta Req. ex Bertol.

The genus Aegilops L. comprises 22 annual wild species that are closely related to wheat (Hammer in Kulturpflanze 28: 33–180, 1980). Aegilops neglecta Req. ex Bertol. is a member of the Aegilops section of this genus and is distributed from Morocco and Spain in the west to Transcaucasia and western Iran in the east. This species includes tetraploid (2n = 28, genome UUMM) and hexaploid forms (2n = 42, UUMMNN). However, the geographical distributions of the two cytological forms remain unclear. Clarifying the distribution of the two cytological forms is essential for a better understanding of the diffusion of Ae. neglecta and its tetraploid and hexaploid forms. In the present study, chromosome numbers were determined for accessions of Ae. neglecta from a total of 137 populations, located in the western area of the species distribution from the Aegean Islands to Morocco. Taken together with previous studies, the present data reveal a difference in the geographical distribution of tetraploid and hexaploid forms: tetraploid form is distributed in the eastern part of the species area and hexaploid form predominantly occurs in the western part with their border on the western margin of the Aegean Sea. Near the border, tetraploid and mixed populations are sporadically found among hexaploid populations in the Balkan and Peloponnesus Peninsulas, while a few hexaploid and mixed populations are found among tetraploid populations in the East Aegean Islands and West Anatolia.     

Agro-morphological traits of <Emphasis Type="Italic">Cicer reticulatum</Emphasis> Ladizinsky in comparison to <Emphasis Type="Italic">C. echinospermum</Emphasis> P.H. Davis in terms of potential to improve cultivated chickpea (<Emphasis Type="Italic">C. arietinum</Emphasis> L.)

Germplasm collections of C. reticulatum and C. echinospermum are limited, while both species face threats from over-grazing and habitat change in their natural environments. Recently many new accessions of C. reticulatum and C. echinospermum were collected in east and south-east Anatolia (Turkey) but they have not yet been evaluated for agro-morphological traits. Therefore, the current study investigated agro-morphological traits of new germplasm sources of C. reticulatum and C. echinospermum and evaluated resistance to biotic and abiotic stresses for chickpea improvement. The most attractive agro-morphological traits were canopy width, number of stems and pods per plant and biological yield. The most productive accessions of C. reticulatum and C. echinospermum had 712 and 625 pods per plant, respectively. Two distinct seed, flower and leaf shapes were found in accessions of C. echinospermum. Path analyses indicated that biological yield and harvest index had the most direct influence on seed yield in both species. Factor analyses showed that high seed yield in C. reticulatum depended on high biological yield and number of pods per plant, whereas high seed yield in C. echinospermum depended on harvest index. It was concluded that most accessions of C. reticulatum and C. echinospermum were not only resistant to some biotic and abiotic stresses but also had hidden alleles that could produce transgressive segregation in crosses to cultivated material.     

Characteristics of the root system in the diploid genome donors of hexaploid wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

Wild crop relatives are of considerable interest in plant breeding and significant efforts have been made to transfer their genetic variation into modern crops. Of the three diploid progenitors of bread wheat (Triticum aestivum L.), only Aegilops tauschii Coss. has been explored and exploited and only for some above ground characteristics. The three wild progenitors (Aegilops speltoides Tausch., Triticum urartu Tumanian ex Gandilyan, and Aegilops tauschii) have never been assayed for root traits. Here we report such a root study, and include Triticum monococcum L. subsp. boeoticum (Boiss.) Hayek and T. turgidum L. subsp. dicoccoides (Koern. ex Asch. et Graebn.) Thell. Fifteen accessions were selected from the above wild species and tested in the presence of one bread wheat cultivar Pavon F76. Significant variation was observed between and within the taxa. Of all accessions tested, cv. Pavon F76 had the smallest root system at maturity while A. speltoides had the largest root system. Moreover, Aegilops spp. had larger mean values for root biomass when compared with Triticum spp. These results suggest there is significant unexplored potential for the use of wheat wild relatives in wheat breeding to improve the root system, or to develop synthetic mapping populations to study root traits.     

Genetic diversity in tolerance of wild <Emphasis Type="Italic">Avena</Emphasis> species to aluminium (Al)

An evaluation of diversity of aluminium (Al) tolerance of 180 genebank accessions of diploid, tetraploid and hexaploid of wild Avena species from the world collection of the N.I. Vavilov Institute of Plant Genetic Resources (VIR) showed that the accessions with a high degree of aluminium tolerance belonged to the diploids A. canariensis, A. longiglumis and A. wiestii, the tetraploids A. barbata, A. vaviloviana, and hexaploids A. ludoviciana and A. sterilis. A comparison of the data on Al tolerance with the soil conditions demonstrated that most highly tolerance accessions tend to be collected on different type of soils. According to the results of the principal component analysis, preliminary screening for Al tolerance can be carried out among hexaploid species with higher degree of plant resistance to pathogens.     

Investigation and evaluation of wild <Emphasis Type="Italic">Iris</Emphasis> resources in Liaoning Province,China

There were 15 species and two variants of wild Iris recorded in Liaoning Province, where is a primary distribution area of Iris in China. According to the division of distribution area for wild plants in Liaoning, twenty-eight sites were selected for investigating wild Iris resources in Liaoning. Distribution, habitat and main accompanying plants of each Iris species were recorded. Fifty-three accessions were collected during the investigation and introduced to suitable environment. Morphological characteristics of each accession were observed. According to previous literatures and specimens, all accessions were identified and classified into 12 species and two variants. The analytic hierarchy process (AHP) was used to perform a comprehensive assessment on the ornamental value of 11 Iris species. The results showed that Iris tigridia Bunge and Iris ensata Thunb. had better ornamental value than the other species. Some suggestions for revision and classification were discussed on several Iris species.     

Retrotransposon-based sequence-specific amplified polymorphism markers for the analysis of genetic diversity and phylogeny in <Emphasis Type="Italic">Malus</Emphasis> Mill. (Rosaceae)

Sequence-Specific Amplified Polymorphism (S-SAP)-analysis of 131 accessions of different species from five sections of the genus Malus was carried out to study genetic diversity, and to clarify phylogenetic and taxonomic issues. S-SAP-markers, based on long terminal repeat (LTR)-retrotransposons TRIM2 and dem1, were developed, which identified 679 polymorphic fragments in the studied Malus species. S-SAP technique proved to be effective for taxonomic studies in Malus. The obtained results generally support the existing sectional taxonomy in the genus Malus and allowed to determine the taxonomic status of some Russian landraces. The genetic diversity and taxonomic status of the Russian apple Antonovka landraces, widely used in breeding programs for their increased adaptation to abiotic stress and scab resistance, were clarified. All of them belong to M. domestica, section Malus. However, Antonovka Olginskaya might have a hybrid origin with some contribution from Gymnomeles species according to PCO analysis data. The taxonomic status was resolved for another Russian landrace, Yakutskaya, which exhibits increased winter hardiness and drought resistance; it belongs to section Gymnomeles, with a high resemblance to M. baccata.