Original Cultivar Research Articles

Comparative transcriptome analysis to identify fruit coloration-related genes of late-ripening litchi mutants and their wild type

Litchi (Litchi chinensis Sonn.) is an important subtropical fruit crop with high economic and nutritional values. Fruit coloration is a sign of litchi fruit ripening and an important external quality traits. Two continuous generations of mutants, named MS1 and MS2, originally derived from cultivar ‘Heli’, exhibited the distinctive characteristic of late maturation of 20 d, with observable delays in coloration. The present study aimed to understand the mechanism underlying maturation difference between ‘Heli’ and its two mutants. An RNA-seq analysis revealed 6,145 differentially expressed genes, mostly identified at the color-breaking stage. The maximum expression levels of some genes involved in anthocyanin biosynthesis and chlorophyll degradation were delayed in the pericarp of the mutants compared with in the original cultivar. Generally, they peaked at earlier stages (S2/S3) in ‘Heli’, compared with later stages (S4/S5) in mutants. Moreover, some hormonal signal receptors, especially those involved in abscisic and ethylene signaling pathways, were also differentially expressed between the original cultivar and the mutant. Transcription factors, including MYB, bHLH, bZIP, and WRKY, correlated with anthocyanin biosynthesis, chlorophyll degradation and abscisic acid signal pathways were identified. The late pigmentation in mutants was related to the fruit ripening program, a complex and comprehensive process. Additionally, we identified novel candidate genes that are involved in the regulation of litchi fruit pigmentation of and gained significant insights into the process of litchi fruit ripening.

‘Chemlali Mhassen’: New olive cultivar derived from crossbreeding program in Tunisia with high oil quality and productivity

The new olive cultivar ‘Chemlali Mhassen’ was derived from the autopollination of the Tunisian oil cultivar ‘Chemlali Sfax’. The main morphological differences between the two cultivars were observed on the endocarp (symmetry, position of maximum diameter, apex, base and surface). On the agronomic plan, this cultivar is distinguishable from the original cultivar due to its medium earliness of bearing (4 years), medium alternate bearing (0.44), early ripening, moderate sensitivity to verticillium and its high olive production per tree (7.7 kg). Concerning oil quality, ‘Chemlali Mhassen’ had higher performances than the original cultivar for oleic acid content (70 to 77 %) and lower contents for palmitic acid (9.2 to 11.5 %) and linoleic acid (9.3 to 14.7 %). Similar performances were recorded between the new and the original cultivars for rhizogenesis behavior and pollen compatibility.

Genetic diversity in wild species and cultivars of strawberry for the FanAAMT gene controlling fruit flavor volatiles

Background. An important consumer trait of strawberry fruits is their aroma. Methyl anthranilate makes a considerable contribution to the fruit flavor. The methyl anthranilate content in strawberry fruits is controlled by the FanAAMT (аnthranilic acid methyltransferase) gene. Identification of genetic determinants for this trait facilitates targeted selection of promising forms based on diagnostic DNA markers. The purpose of this study was to study the allelic diversity of the FanAAMT fruit flavor gene in wild strawberry species and strawberry cultivars for identification of promising genotypes.Materials and methods. The objects of this study were wild species of Fragaria L. as well as F. × anaschata Kantor. and F. × ananassa Duch. cultivars of different ecogeographic origin. The FanAAMT gene was identified with the dominant marker FanAAMT.Results and conclusion. In the analyzed collection of strawberry genotypes, the FanAAMT gene was identified in 36.4% of the forms, including the wild species F. vesca L., F. moschata Duch. and F. virginiana subsp. platypetala (Rydb.) Staudt, and cv. ‘Kupchikha’ (F. × anaschata). Among the analyzed F. × ananassa cultivars, the FanAAMT gene was found in 31.6% of the tested forms, specifically in 27.3% of the 22 Russian cultivars, and 37.5% of the analyzed foreign ones. Promising sources of high methyl anthranilate content in fruits were identified: wild spp. F. moschata, F. vesca, and F. virginiana subsp. platypetala; cv. ‘Kupchikha’ (F. × anaschata); Russian garden strawberry cvs. ‘Bylinnaya’, ‘Zenit’, ‘Lastochka’, ‘Neznakomka’, ‘Feyerverk’ and ‘Tsarskoselskaya’; and foreign garden strawberry cvs. ‘Karmen’, ‘Ostara’, ‘Samson’, ‘Symphony’, ‘Troubadour’ and ‘Vima Tarda’, in which the functional allele of the FanAAMT gene was found. In the remaining studied strawberry genotypes the marker FanAAMT was not detected, which presumably indicates that the FanAAMT gene is absent. cells (R9.4.1).

Habituation to thaxtomin A increases resistance to common scab in 'Russet Burbank' potato.

Common scab is a potato disease characterized by the formation of scab-like lesions on the surface of potato tubers. The actinobacterium Streptomyces scabiei is the main causal agent of common scab. During infection, this bacterium synthesizes the phytotoxin thaxtomin A which is essential for the production of disease symptoms. While thaxtomin A can activate an atypical programmed cell death in plant cell suspensions, it is possible to gradually habituate plant cells to thaxtomin A to provide resistance to lethal phytotoxin concentrations. Potato ‘Russet Burbank’ calli were habituated to thaxtomin A to regenerate the somaclone RB9 that produced tubers more resistant to common scab than those obtained from the original cultivar. Compared to the Russet Burbank cultivar, somaclone RB9 generated up to 22% more marketable tubers with an infected tuber area below the 5% threshold. Enhanced resistance was maintained over at least two years of cultivation in the field. However, average size of tubers was significantly reduced in somaclone RB9 compared to the parent cultivar. Small RB9 tubers had a thicker phellem than Russet Burbank tubers, which may contribute to improving resistance to common scab. These results show that thaxtomin A-habituation in potato is efficient to produce somaclones with increased and durable resistance to common scab.

Walnut (J. regia) Agro-Residues as a Rich Source of Phenolic Compounds.

Simple SummaryAgro-residues are usually discarded as landfill, or burnt or left to decompose in the orchard. The efficient use of these walnut agro-residues would be a strategy that simultaneously helps to preserve the environment and boosts the economic outcome for farmers and companies. While some studies have reported on the content of bioactive compounds in walnut husks, little or nothing is known to date about the bioactive compounds in the buds and bark. Potentially, if walnut parts are used as a valuable source of bioactive compound, they might still be reused for other purposes. The identification and quantification of new phenolics between the different parts of the plant was carried out. It provided valuable data on their phenolic contents, and demonstrated where the extraction of individual phenolics would be meaningful. These data also show origin-related phenolic contents across the cultivars, and thus these phenolic profiles might serve to define the origins of different walnut cultivars. The study will help to propose new directions for further studies essential for agro-food, cosmetics and pharmacy industries.The present study was designed to identify and quantify the major phenolic compounds (phenolics) in the inner and outer husks, buds and bark of the Persian walnut, Juglans regia L. A comparison across six different cultivars grown in Slovenia was also carried out: ‘Fernor’, ‘Fernette’, ‘Franquette’, ‘Sava’, ‘Krka’ and ‘Rubina’. A total of 83 compounds were identified, which included 25 naphthoquinones, 15 hydroxycinnamic acids, 8 hydroxybenzoic acids, 13 flavanols, 2 flavones, 1 flavanone and 19 flavonols. For the first time, 38 phenolics in the husks, 57 phenolics in the buds and 29 phenolics in the bark were presented in J. regia within this study. Naphthoquinones were the major phenolics determined, approximately 75% of all analysed phenolics in the inner husk, 85% in the outer husk, 50% in buds and 80% in bark. The highest content of phenolics was found in the walnut buds, followed by the bark, the inner husk and the outer husk. On the basis of these high phenolic contents, walnut husks, buds and bark represented valuable by-products of the walnut tree. These data also show origin-related phenolic contents across the cultivars, and thus these phenolic profiles might serve to define the origins of different walnut cultivars.

Concentrations of Phenolic Acids Are Differently Genetically Determined in Leaves, Flowers, and Grain of Common Buckwheat (Fagopyrum esculentum Moench).

Common buckwheat (Fagopyrum esculentum Moench) is a valuable source of proteins, B vitamins, manganese, tryptophan, phytochemicals with an antioxidant effect, and the natural flavonoid rutin. Due to its composition, buckwheat supports the human immune system, regulates blood cholesterol, and is suitable for patients with diabetes or celiac disease. The study aimed to compare the allocation of selected phenolic acids (neochlorogenic acid, chlorogenic acid, trans-caffeic acid, trans-p-coumaric acid, trans-sinapic acid, trans-ferulic acid) and flavonoids (rutin, vitexin, quercetin, kaempferol) in the leaves, flowers, and grain of buckwheat cultivars of different origin. The content of individual phenolics was determined by the HPLC-DAD method. The results confirmed the determining role of cultivar on the relative content of chlorogenic acid, trans-caffeic acid, trans-sinapic acid, vitexin, and kaempferol in buckwheat plants. A significantly negative correlation among concentrations of phenolic acids in different common buckwheat plant parts shows that there are different mechanisms of genetic influences on the concentration of phenolic substances in common buckwheat flowers, leaves, and grain. These differences should be taken into account when breeding buckwheat for a high concentration of selected phenolic substances.

Evaluation of Protein and Antioxidant Content in Apricot Kernels as a Sustainable Additional Source of Nutrition

Apricot fruits are a favorite for consumption; however, their kernels are a rich source of nutritionally interesting substances, too. Nevertheless, in processing of apricots, the kernels remain often unused. In this study, 32 cultivars of different origin were analyzed for their protein content and content of secondary metabolites (phenolics and flavonoids). The weight and taste of kernels were assessed and these data were summarized for an evaluation of the attractiveness of the studied apricot kernels. Results showed that the protein content of kernels ranged from 14.56% to 28.77% and did not depend on the origin or weight of kernel, or taste. In addition, total phenolic (63.5–1277.3 mg GAE/100 g DW) and total flavonoid (0–153.1 mg CE/100 g DW) contents and antioxidant capacity (483.4–2348.4 mg TE/100 g DW) were measured in kernels. In conclusion, the Czech hybrids LE-5959, LE-5500 and French cultivar Koolgat are prospective for kernel processing and consumption because of their high protein content and sweet taste. Hybrid LI-3-6, originating in China, showed high protein content as well but because of bitter taste could be useful rather in medicine.

Extraction and classification of origin characteristic peaks from rice Raman spectra by principal component analysis

Rice origin identification can provide brand protection for rice with geographical indications. Therefore, it is necessary to design a convenient and fast detection method to meet the demands of the market. Based on Raman spectroscopy, this study involved the extraction and classification of characteristic spectral peaks of rice grain samples of the same cultivar but different places of origin. Raman spectra were acquired from 80 samples of rice with four different places of origin (Longjing 31 cultivar), and spectral information was extracted for analysis. First, the rice spectra were pretreated using a baseline correction and range normalization. Second, from the 400−1600cm−1 and 2800−3200cm-1 spectral region starting from the first four principal components of the regression coefficients extracted from principal component analysis (PCA), further screening produced eight spectral peaks characteristic of the place of origin: 476 cm−1, 867 cm−1,940 cm−1, 1121 cm−1, 1342 cm−1, 1384 cm−1, 1462 cm−1, and 2914 cm−1. These were also assigned to functional groups, revealing subtle differences in the nutritional content dependent on place of origin. Third, eight characteristic values extracted by PCA were used to establish a four-layer 8-9-6-4 (input-hidden-hidden-output) back propagation (BP) neural network structure as a rice-origin identification model. Finally, the model was used to train 80 rice samples in place-of-origin classification, and the average prediction accuracy of the cyclic test for the training samples reached 97.5 % after five epochs; for the other four epochs the accuracy ranged from 98.75%–96.25%. These results show that the model is feasible as a tool for the identification of rice types of the same variety and that it can effectively identify rice from different areas.

The origin of Asian pear cultivars inferred from DNA markers

The origin of Asian pear cultivars inferred from DNA markers

Characterization of watermelon local cultivars from Southern Tunisia using morphological traits and molecular markers

In Southern Tunisia, local cucurbitaceous genetic diversity is threatened by the introduction of many commercial varieties. In the present study, the genetic diversity of local Tunisian watermelon cultiavrs and two commercial varieties (Giza and Sugar-baby) was studied using morphological traits and RAPD markers. The morphological analysis showed an important diversity among the studied watermelon cultivars. The principal component analysis based on 15 morphological traits explained 67.85% of the total variation and showed a clear classification of the cultivars into several groups. Geographical origin was correlated with seed weight and thickness of pericarp parameters. RAPD primers generated 86 reproducible bands, of which 85 were highly polymorphic. The AMOVA showed significant inter-population differentiation (28%). The principal coordinate analysis indicated that commercial varieties are significantly different from the local cultivars. The commercial varieties have the highest PhiPT when compared to the local cultivars. No correlation between the RAPD markers and the geographical origin of the watermelon cultivars was found. However, a significant correlation was found between RAPD markers and some fruit characteristics such as seed weight and fruit acidity. The results obtained from this study provide new data about the genetic diversity of Tunisian watermelon local germplasm, which constitue the first step for the establishment of a core collection of the Tunisian watermelon germplasm and would be useful for the preservation of these local resources and their use in future breeding programs.

Tracing the origins of hybrids through history: monstrous cultivars and Napoléon Bonaparte’s exiled paper daisies (Asteraceae; Gnaphalieae)

Abstract Golden everlasting paper daisies (Xerochrysum, Gnaphalieae, Asteraceae) were some of the earliest Australian native plants to be cultivated in Europe. Reputedly a favourite of Napoléon Bonaparte and Empress Joséphine, X. bracteatum is thought to have been introduced to the island of St Helena in the South Atlantic during Napoléon’s exile there. Colourful cultivars were developed in the 1850s, and there is a widely held view that these were produced by crossing Xerochrysum with African or Asian Helichrysum spp. Recent molecular phylogenetic analyses and subtribal classification of Gnaphalieae cast doubt on this idea. Using single-nucleotide polymorphism (SNP) data, we looked for evidence of gene flow between modern cultivars, naturalized paper daisies from St Helena and four Xerochrysum spp. recorded in Europe in the 1800s. There was strong support for gene flow between cultivars and X. macranthum. Paper daisies from St Helena were genotypically congruent with X. bracteatum and showed no indications of ancestry from other species or from the cultivars, consistent with the continuous occurrence of naturalized paper daisies introduced by Joséphine and Napoléon. We also present new evidence for the origin of colourful Xerochrysum cultivars and hybridization of congeners in Europe from Australian collections.

Olive (Olea europaea L.) Genetic Transformation: Current Status and Future Prospects.

Olive (Olea europaea L.) is the most characteristic and important oil crop of the Mediterranean region. Traditional olive cultivation is based on few tens cultivars of ancient origin. To improve this crop, novel selections with higher tolerance to biotic and abiotic stress, adaptable to high-density planting systems and resilient to climate change are needed; however, breeding programs are hindered by the long juvenile period of this species and few improved genotypes have been released so far. Genetic transformation could be of great value, in the near future, to develop new varieties or rootstocks in a shorter time; in addition, it has currently become an essential tool for functional genomic studies. The recalcitrance of olive tissues to their in vitro manipulation has been the main bottleneck in the development of genetic transformation procedures in this species; however, some important traits such as fungal resistance, flowering or lipid composition have successfully been manipulated through the genetic transformation of somatic embryos of juvenile or adult origin, providing a proof of the potential role that this technology could have in olive improvement. However, the optimization of these protocols for explants of adult origin is a prerequisite to obtain useful materials for the olive industry. In this review, initially, factors affecting plant regeneration via somatic embryogenesis are discussed. Subsequently, the different transformation approaches explored in olive are reviewed. Finally, transgenic experiments with genes of interest undertaken to manipulate selected traits are discussed.

Features of the phenological phases of introduced strawberry cultivars in the conditions of the Orel region

Relevance.The study of the timing and duration of individual phases of the development of strawberry cultivars of different ecological and geographical origin in these climatic conditions is of great practical importance. The purpose of the study was the determination of the timing of the main phenophases of introduced strawberry cultivars in the Orel region, the compliance of the phenorhythms of the studied cultivars with climatic conditions, as well as the ranking of the cultivars by the terms of flowering and maturation.Methods and materials.The article presents the results of phenological observations for the period 2016-2019. 34 strawberry cultivars of domestic and foreign selection were studied. The research was carried out at the VNIISPK site of primary variety study.Results. Based on long - term observations, on the time of entry into the flowering and fruiting phase, the cultivars were ranked into early, medium and late-maturing. The influence of effective temperatures on the onset of phenophases was analyzed. The sum of effective temperatures necessary for the beginning of flowering of strawberry cultivars of different maturation periods in the conditions of the Orel region was determined. For the onset of strawberry flowering, it takes from126.68 to 260.37°effective temperatures. Early cultivars need the sum of effective temperatures of 126.68-197.55°, cultivars of middle maturation need 146.31-225.44°, late cultivars - 159.93-260.37 depending on the year of study. Fruiting occurs at the sum of effective temperatures in early cultivars from 351.73°C to 465.43°C, in middle-maturing cultivars from 390.96 to 535.44°C, in late-maturing cultivars from 450°C to 649°C.

Interspecific hybridization contributes greatly to the origin of Asian pear cultivars – a Case study of pears from Gansu province of China

Interspecific hybridization contributes greatly to the origin of Asian pear cultivars – a Case study of pears from Gansu province of China

Constitutive activation of nitrate reductase in tobacco alters flowering time and plant biomass

Pyridine alkaloids produced in tobacco can react with nitrosating agents such as nitrite to form tobacco-specific nitrosamines (TSNA), which are among the most notable toxicants present in tobacco smoke. The market type known as burley tobacco is particularly susceptible to TSNA formation because its corresponding cultivars exhibit a nitrogen-use-deficiency phenotype which results in high accumulation of nitrate, which, in turn, is converted to nitrite by leaf surface microbes. We have previously shown that expression of a constitutively activated nitrate reductase (NR) enzyme dramatically decreases leaf nitrate levels in burley tobacco, resulting in substantial TSNA reductions without altering the alkaloid profile. Here, we show that plants expressing a constitutively active NR construct, designated 35S:S523D-NR, display an early-flowering phenotype that is also associated with a substantial reduction in plant biomass. We hypothesized that crossing 35S:S523D-NR tobaccos with burley cultivars that flower later than normal would help mitigate the undesirable early-flowering/reduced-biomass traits while maintaining the desirable low-nitrate/TSNA phenotype. To test this, 35S:S523D-NR plants were crossed with two late-flowering cultivars, NC 775 and NC 645WZ. In both cases, the plant biomass at harvest was restored to levels similar to those in the original cultivar used for transformation while the low-nitrate/TSNA trait was maintained. Interestingly, the mechanism by which yield was restored differed markedly between the two crosses. Biomass restoration in F1 hybrids using NC 645WZ as a parent was associated with delayed flowering, as originally hypothesized. Unexpectedly, however, crosses with NC 775 displayed enhanced biomass despite maintaining the early-flowering trait of the 35S:S523D-NR parent.

Patterns of genetic structure and evidence of Egyptian Citrus rootstock based on informative SSR, LTR-IRAP and LTR-REMAP molecular markers

BackgroundReleasing the draft genome of sweet orange provides useful information on genetic structure and molecular marker association with heritable breeding traits in citrus species and their structures. Last decades, microsatellite and retrotransposons are well known as a significant diverse component of the structural evolution. They represented the most potent elements for assessing sustainable utilization of the complicated classification in citrus breeding. Our study was performed to verify the structure analysis and the parentage genetic diversity among the Egyptian citrus rootstocks and the related species. ResultsHere, the performance of 26 SSR and 14 LTR-IRAP in addition to 20 LTR-REMAP markers have been used to conduct the discriminating power and the status of the genetic structure analysis among twenty specimens of citrus genotypes. As a result, the three markers approach exhibited a remarkable variation among the tested genotypes. Overall, the three markers have different discrimination power; the co-dominant SSR markers can differentiate within the group level only in addition to the species level of sour orange, while the dominant markers LTR-IRAP had the ability to discriminate among the group level in addition to species level and the origin of acids. Similarly, LTR-REMAP is suitable for classifying the group level and species level for mandarins as well the origin of Egyptian acids; probably due to it is integration of SSR and LTR-IRAP techniques. Structure and PCoA results of LTR-REMAP marker in strong support for the group structure of citrus species have been divided into four sets: acids, grapefruit/pummelo, mandarin/orange, and sour orange. ConclusionOur findings of the genetic structure analysis support the monophyletic nature of the citrus species; are able to provide unambiguous identification and disposition of true species and related hybrids like lemon, lime, citron, sour orange, grapefruit, mandarin, sweet orange, pummelo, and fortunella; and resulted in their placement in individual or overlap groups. The outcomes of these results will offer helpful and potential information for breeding programs and conservation approaches as a key stage toward identifying the interspecific admixture and the inferred structure origins of Egyptian citrus rootstock and acid cultivars.

Origin and traits of traditional Spanish peach cultivars preserved in the BAGERIM

Origin and traits of traditional Spanish peach cultivars preserved in the BAGERIM

Stress resistance in barley cultivars of various agroecological origin under extreme continental climate conditions

Background. The barley collection at the N.I. Vavilov AllRussian Institute of Plant Genetic Resources (VIR), being the main source of source material for breeding, is insufficiently studied under conditions of extreme continental climate. The purpose of the research was to assess the adaptability of barley cultivars held by VIR to extreme continentality.Material and methods. The research targets were 24 barley cultivars representing various breeding centers and tolerance regions of Russia. The cultivar ‘Omsky 91’ developed at Omsk Agrarian Scientific Center was used as the reference.Results and discussion. According to the genetic profiles for alleles of hordein-coding loci, provided by the Vavilov Institute of General Genetics, more than 70% of the studied barley cultivars (‘Chelyabinsky 99’, ‘Priazovsky 9’, ‘Zadel’, ‘Sokol’, ‘Zernogradsky 584’, ‘Zadonsky 8’, ‘Khadzhibey’, ‘Beatrice’, ‘Knyazhich’, ‘Zevs’, ‘Kazak’) were linear in their hordein-coding loci. The homeostasis of the cultivars, their stability indices and plasticity levels were calculated. Their intensity measures and selection differentials were determined.Conclusion. The adaptability assessment based on the sum of ranks (calculated using the abovementioned adaptability parameters) showed that the monomorphic cultivars ‘Priazovsky 9’ and ‘Chelyabinsky 99’ as well as cv. ‘Severyanin’ (not listed in the State Register for Selection Achievements) were most adapted to extreme continental climate conditions (sums of ranks ranged from 8 to 29). The adaptability of the identified cultivars was confirmed by high-yielding hybrid populations produced from crossing the selected adaptable cv. ‘Chelyabinsky 99’ with cvs. ‘Omsky 91’ and ‘Omsky 95’ released by Omsk Agrarian Scientific Center. The obtained lines demonstrated higher yields than both the mean yield of the parent cultivars (+1.20 t/ha) and the yield of the best parent cultivar (+0.76 t/ha).

Classification of environments based on correlations of yield in spring bread wheat

Background.Genotype–environment interaction complicates selection of lines in plant breeding. Researchers have developed different ways to classify environments to mitigate its effect. The use of correlation analysis between yields of cultivars grown in different environments was earlier proposed for classification of these environments.The aim of this researchwas to classify years on the basis of correlations of the yields in a specially selected set of spring bread wheat cultivars and to verify the application of such classification to breeding material in different nurseries.Materials and methods. The material for the experiment included cultivars, lines and breeding samples from the collection nursery, competitive variety trials, and the nursery for segregating populations, respectively. The experiments were conducted from 2010 through 2017. The correlation analysis between the yields of 19 marker cultivars of different ecogeographic origin was used as the basis for the classification of years. The calculated correlation parameters for the yields of marker cultivars and those of the breeding material in nurseries for the same pairs of years were compared using the Mann–Whitney U-test.Results. The years under consideration were classified into three groups: 1) 2010 and 2013; 2) 2011, 2012 and 2014; 3) 2015, 2016 and 2017. Correlations between the yields of the marker cultivars showed no significant differences from those of the genotypes from other nurseries across the analyzed years. Consequently, the classification of years based on the reactions of marker cultivars can be justifiably extended onto other breeding material.Conclusion. It is suggested to select and use a set of marker cultivars in multi-environment trials to obtain additional information about target environments and make more informed decisions on culling plant breeding materials.

The role of Prunus cerasifera Ehrh. in the origin, evolution and improvement of stone fruit cultivars

At Krymsk Experiment Breeding Station of VIR, as a result of collecting, studying, and selective use of myrobalan plum genetic diversity, the intraspecific taxonomy of the species Prunus cerasifera Ehrh. was clarified. Donors of traits significant for breeding were identified and, with their use, adaptable cultivars of myrobalan plum, Russian plum and clonal rootstocks of stone fruit plants were developed.Intraspecific classification of P. cerasifera is proposed, with the identified subspecies:subsp. cerasifera (typical myrobalan plum);subsp. orientalis (M. Pop.) Erem. et Garcov. (Oriental myrobalan plum);and subsp. macrocarpa Erem. et Garcov. (large-fruited myrobalan plum).Within subsp. P. cerasifera subsp. macrocarpa, varieties were identified:var. macrocarpa (typical, or Krymsk);var. georgica Erem. et Garcov. (Georgian);var. iranica (Koval.) Erem. et Garcov. (Iranian);var. nairica (Koval.) Erem. et Garcov. (Armenian);var. pissardii Carr. (Pissard);and var. taurica (Kost.) Erem. et Garcov. (Taurida).The participation of myrobalan plum in the origin of spp. P. brigantiaca Vill., P. cocomilia Tem., and P. spinosa L. was traced. Involvement of large-fruited myrobalan plum in hybridization with blackthorn contributed to the manifestation of an exceptional polymorphism among the varieties of the hybridogenic species P. domestica L. (P. cerasifera × P. spinosa). As a result of hybridization between myrobalan plum and Chinese plum varieties, a new cultigen species emerged – Russian plum (× P. rossica Erem.). By now, 127 cultivars of this species and 7 clonal rootstocks for stone fruit crops have been developed. These cultivars and clonal rootstocks are zoned for Russia and a number of other countries.