Background. The vegetation in Astrakhan Province has for a long time attracted the interest of natural scientists. However, due to inaccessibility of a number of habitats and ‘landscape fluidity’ in the Volga-Akhtuba floodplain and the Volga estuary, not all of its areas have been explored comprehensively enough. The local vast resources of useful plants of arid steppes and deserts, including crop wild relatives (CWR), have until now remained unused. Studying and mobilizing valuable plant samples, forms and species from natural communities would help to preserve the bioresources of desertified steppes and deserts, and enhance their utilization in arid areas.

Methods. The collecting mission’s route passed through Chernoyarsky, Yenotaevsky, Narimanovsky, Krasnoyarsky, Kharabalinsky, Akhtubinsky, Privolzhsky, Kamyzyaksky, Limansky and Ikryaninsky districts of Astrakhan Province. With the itinerary-based method of surveying, the explorations were carried out from August 12 through August 30, 2017. The length of the route was 2,467 km. Coordinates of the collecting sites and altitudes above sea level were identified with a Garmin etrex 20x navigation device.

Results. The diversity of CWR and landraces was explored in various natural ecosystems of the Volga river basin. Sixty-eight phytocenoses were described, and 160 seed samples of 39 plant species (25 genera) were collected, representing old landraces and wild relatives of fodder, fruit, cereal, vegetable and fiber crops. Many of the collected plant forms and populations with valuable biological traits deserve to be included in introduction trials and breeding programs, especially those that may serve as sources of heat, drought and salt tolerance.

 Background. Studying the effect of phytohormones and light on the germination of apple pollen with reduced viability on an artificial nutrient medium is of importance, because it may facilitate an increase in the germination percentage among plant samples promising for breeding after their long-term preservation under low temperatures.

Materials and methods. Pollen viability of the apple-tree cultivar ‘Krasnolistnaya’ was measured by germinating it on an artificial nutrient medium containing 10% sucrose solution and 0.8% agar. Drops of a distilled water suspension of pollen with added phytohormones were applied to the surface of the nutrient medium. Pollen was germinated in the dark (24 hours in a thermostat at 21°C) and under light (in an artificial light chamber at 21°C with a photoperiod of 16 hours of light / 8 hours of darkness). Results. Pollen of cv. ‘Krasnolistnaya’ with reduced viability most effectively germinated with the use of gibberellin at a concentration of 1 mg/l and 10 mg/l: the germination percentage was 22.3±0.8% and 21.8±1.3% respectively (сf. 10.9±1.5% in the reference). The most effective combination of phytohormones was gibberellin 10 mg/l + kinetin 10 mg/l – the percentage of germination was 22.8±6.3%; kinetin 1 mg/l + indolylbutyric acid 1 mg/l – the percentage of germination was 17.5±5.9% vs. 10.9±1.5% in the reference.

Conclusion. Phytohormones were observed to have a significant effect on the germination of apple pollen with reduced viability. Effective concentrations and combinations of phytohormones that promote the germination of pollen with reduced viability have been identified. Light does not affect the germination of pollen with reduced viability.

Background. Preservation of the entire genetic diversity of the world’s flora is indispensable to the deployment of breeding practice aimed at development and improvement of the existing economically useful plant species and varieties. The in situ conservation approach is recognized as the topmost priority. Therefore, a study of crop wild relatives (CWR) in Kaliningrad Province appears vital to identify the most vulnerable species and enhance their in situ conservation.

Materials and methods. Crop wild relatives occurring in Kaliningrad Province were the research target. The WIR and LE herbarium collections, published data, and results of VIR’s plant explorations undertaken in 1974 and 1983 served as the material for the research. Plant species included in the Red Data Books of Kaliningrad Province, Lithuania, Estonia, Poland, etc. were analyzed, and the data from open databases (GBIF, CWR, ILDIS, etc.) and AgroAtlas maps were employed. CWR requiring special conservation measures were identified.

Results and conclusions. Kaliningrad Province, Russia, is home to 324 species of CWR. Natural habitats of the 6 most vulnerable plant species were mapped: Vicia dumetorum L., Trifolium rubens L., Chrisaspis spadiceum L., Elytrigia juncea (L.) Nevski, Phleum phleoides (L.) H. Karst., and Allium vineale L. These species fall under the 1st vulnerability category.

Background. Spring bread wheat is the main export crop in Kazakhstan. Unfortunately, wheat varieties cultivated for large-scale production do not fully meet the requirements of agricultural producers. The world diversity of wheat genetic resources should be widely used in breeding programs in order to develop new wheat cultivars with stable yields and with resistance to adverse environmental factors.

Materials and methods. One hundred collection accessions of spring bread wheat were studied in 2015–2017 at the A.I. Barayev Science and Production Center of Grain Farming, Ltd. Seeds were sown at an optimum time (May 20–25), using an SSFC-7 seeder. Harvesting was conducted with a Wintersteiger combine. The study of the collection material was carried out in accordance with the guidelines developed by the N.I. Vavilov Institute of Plant Genetic Resources (VIR). The protein content was measured in line with State Standard 10846-91. The method of sodium dodecyl sulfate (SDS) sedimentation, modified by V. M. Bebyakin and M. V. Buntina, was used to measure the level of sedimentation.

Results and conclusion. During the three-year study of spring bread wheat accessions in Northern Kazakhstan, only the cultivars ‘Shortandinskaya 2012’ and ‘Astana 2’ exceeded the reference ‘Astana’ in yield. The accessions ‘BW 252’, ‘Neepawa’ (Canada), ‘MANITUOU LR 13’ (CIMMYT, Mexico) and ‘Novosibirskaya 29’ (Russia) ripened 1–2 days earlier than the reference, while their average yield for 3 years was almost on the same level with the reference. The cultivars ‘Astana’ (the reference, Kazakhstan), ‘WA007824 WA7824’ (USA), ‘Novosibirskaya 29’, ‘Novosibirskaya 15’ (Russia), ‘OPATA85 LR10’ and ‘LR27+LR31,LR34’ (CIMMYT, Mexico) were distinguished for grain quality due to their high protein content and the level of sedimentation.

Background. Guar or clusterbean (Cyamopsis tetragonoloba (L.) Taub.) is an annual leguminous plant cultivated for feed, food and industrial purposes. Its seed endosperm is used to extract guar gum, so the guar genetic resources stored in the VIR collection are of strategic importance for the import substitution policy in Russia in the context of their prospective introduction into cultivation in the country’s southern areas. Most of the guar accessions had been preserved by VIR for 40 years or more, so the task was to assess their germination rates and restore their viability. In the process of screening, seed quality parameters of the accessions were examined and analyzed.

Materials and methods. VIR’s collection of C. tetragonoloba, initiated by N. I. Vavilov, now contains 111 accessions. Percentage seed viability, germination energy and seed hardness were evaluated in the Long-Term Storage Laboratory for 50 accessions reproduced in 2018 and for 263 older reproductions of 89 guar accessions. In total, 313 seed samples reproduced across 18 different years were analyzed. Statistica 10 software was used to perform a single-factor analysis of variance and find out how germination energy, seed viability and seed hardness correlated with the age of seeds, mean monthly temperature and mean rainfall during the growing season.

Results and discussion. After more than 40 years of storage, the guar accessions did not entirely lost their viability under laboratory and field conditions. Very high positive correlations were found for their percentage viability and germination energy with the mean monthly temperature in the year of reproduction. A weak positive correlation was observed between seed hardness and the year of reproduction. Correlations between seed viability and rainfall during the growing season were weak, with a weak negative correlation between seed hardness and rainfall. The viability level of 30-year-old seeds was 50%, so guar may be regarded as belonging to the group of macrobiotic plants.

Background. Soybeans accessions from the VIR collection were tested in Primorsky Territory, Russia. These accessions had not been studied earlier in that area.

Materials and methods. The testing was carried out at the Far East Experiment Station of VIR and involved 570 soybean accessions of various geographic origin. The work was performed according to VIR’s methodological guidelines.

Results. The selected accessions were evaluated for their flowering and ripening schedule, seed yield, various seed characteristics (primary color of seed coat, seed hilum color, etc.), 1000 seed weight, plant height, the lower pod setting height, etc. The maximum seed yield (18.0–21.9 g) was registered for 4 accessions: ‘Primorskaya 1099’(k-9700), ‘Primorskaya 1102’ (k-9707) (Russia, Primorsky Territory); ‘Epps’(k-9308) and ‘Pioneer 3981’(k-9651) (USA). Their growing season lasted 121– 130 days. The earliest accessions ‘1337’ and ‘738-4’ (Sweden) had growing seasons of 81–90 days and low seed yields. The weight of 1000 seeds varied from 71 g to 250 g. Only one accession had 1000 seed weight higher than 300 g. The correlation between seed yield and growing season duration was medium (r = 0.57), and between seed yield and 1000 seed weight it was small (r = 0.13). Stem length varied from 15–30 to 111–130 cm. Accessions with the highest seed yield had stem lengths of 51–90 cm. The lower pod setting height ranged from a minimal level (< 6.1 cm) to 18.1–20.0 cm. Among the 92 accessions with high seed productivity (> 14.0 g) only 5 produced their lower pods at a height above 12 cm. Full-scale characterization of the material was published in Catalogue of the VIR Global Collection, Issue 905, 2019.

Conclusion. The accomplished study helped to describe earlier untested accessions, grown under the environmental conditions important for soybean production. The accessions with the best economic characteristics can be used in breeding practice.

Background. Table beet (Beta vulgaris L.) is a source of ‘betanin’, a natural food dye known as food additive E-162. The VIR collection holds a large diversity of red beet accessions. It is the base for obtaining source material to breed cultivars with high betanin content.

Materials and methods. In the framework of this study, which lasted from 2015 to 2018, a group of 29 accessions identified during the screening was analyzed. The pigment was assessed at the laboratory of the ECO RESOURCE Joint-Stock Company using Spectrophotometer SF-2000. Field experiments were performed according to VIR’s guidelines in 2015–2017 at Pushkin and Pavlovsk Laboratories of VIR, Volgograd Experiment Station of VIR, and Maikop Experiment Station of VIR.

Results. Environmental and geographic tests demonstrated that the ability to accumulate the pigment was variable among the red beet accessions, and its concentrations were notably different. The research showed that accumulation of betanin is primarily associated with agroclimatic growing conditions. The dynamics of pigment accumulation can be both positive and negative. The optimal zone for growing the studied accession is Leningrad Province, where the highest content of betanin was observed. Mid-ripening and cold-resistant old landraces were a reference point in the search for the desired genotypes.

Conclusion. The process of pigment accumulation is extremely responsive to weather conditions, soil water balance, and watering uniformity. The negative impact of these factors would smooth down the crop’s varietal polymorphism. Diseases and insect pests have led to slowing and stopping the accumulation of betanin. As a result of the comprehensive agroecological study of prototypes, promising accessions were identified and recommended for cultivation in Leningrad Province with the aim of betanin production.

Background. The article deals with the problems faced while studying and maintaining a collection of plant genetic resources against a strong virus infection background.

Materials and methods. The data obtained during 8 years of monitoring over 1000 potato accessions for the incidence of virus diseases are presented. The work was carried out at Pushkin and Pavlovsk Laboratories of VIR and at the Polar Experiment Station of VIR (Khibiny, Arctic Circle). Visual control of the symptoms of the infection was combined with an enzyme-linked immunosorbent assay (ELISA) for potato mosaic viruses Х, S, M and Y.

Results and conclusions. For many years, the global collection of VIR has been studied and maintained under a threat of strong virus infections. Among the viruses that have the widest distribution and cause significant damage to potato, there are viruses M and Y in Pushkin, and Х in Khibiny. Among the infected plant material, accessions with a latent virus infection, manifesting tolerance to the pathogens, have constantly been observed. The conventional point-based principle of scoring field resistance of potato cultivars and hybrids to viruses requires a significant revision. A new alternative approach is proposed for virus resistance assessment, when the clonal reproduction type of the tested accessions is taken into account.

Background. Molecular identification of plant genomes, based on the use of DNA markers, is becoming a reliable tool for cultivar identification. Widespread application of DNA markers will ensure protection of breeders’ rights for plant breeding centers, purity of seed production processes, and transparency of the domestic crop seed market. The system of SSR markers is suitable to solve the problems of identification and genetic profiling of many crops; it could be successfully used on flax and linseed. The aim of this work was to study the polymorphism of a number of modern Russian common flax cultivars and develop their genetic profiles.

Materials and methods. Among the large number of SSR markers (over 1300) used for common flax (Linum usitatissimum L.), the most informative for genotype identification is, in our opinion, the set of 11 SSR primers, characterized by their highest precision. This set of markers was used to study the polymorphism of eleven flax cultivars developed in three geographically diverse locations – Tver, Pskov and Tomsk.

Results and discussion. In the studied group of cultivars 53 alleles were identified: 15 of these appeared to be rare, including 11 unique ones. Each flax sample contained its specific set of alleles. Using the alphabetic code for SSR markers made it possible to develop genetic profiles for more precise genotyping of flax samples hardly distinguishable morphologically, thus providing an opportunity to effectuate genetic profiling for all flax cultivars listed in the State Register of Breeding Achievements in Russia. Cluster analysis with a dendrogram showing genetic similarities helped to find differences among the studied flax samples in their distribution according to the place of their origination and the duration of their growing seasons.

Background. The current natural habitat of Tulipa suaveolens Roth rapidly decreases. In order to work out the strategy of the species’ preservation, evaluation of its intraand interpopulation polymorphism is required.

Materials and methods. Molecular-genetic ISSR markers were used to analyze 125 samples from 10 populations of T. suaveolens occurring in Volgograd Province and 4 populations from Saratov Province.

Results. ISSR analysis revealed high intrapopulation polymorphism (73–89%) in T. suaveolens populations form Volgograd Province. AMOVA attributed the largest proportion of variability (74.3%) to intrapopulation polymorphism. Interpopulation differences account for 25.7%. Total subdivision of populations (F_ST) was 0.257; total gene flow (Nm) between populations was 0.723. According to Bayesian analysis and clustering with both UPGMA and Neighbor Joining methods, all the studied T. suaveolens samples from Volgograd Province make up a large genetic group: within that group none of the potential subgroups may be associated with a particular place of collecting. The NewHybrids software was applied, and the results pointed to the hybrid nature of most samples. Samples of three populations from Saratov Province made up a separate genetic group; those samples fell under the category of parent forms.

Conclusion. Considering that genetic subdivision of T. suaveolens populations within the administrative borders of Volgograd Province is insignificant, while all the province’s natural parks and a number of protected natural areas undertake measures to preserve the species, the existing conservation strategy may be recognized as effective and sufficient.

Background. To optimize the process of bread wheat breeding for earliness and environmental adaptability, searching for new source material is a crucial task. The ultra-early line Rico (k-65588) – Triticum aestivum var. erythrospermum Koern. – stands out among the bread wheat accessions from the VIR collection for its important adaptive features.

Materials and methods. Spring wheat accessions with different speed of development were selected from the VIR collection for this study, along with the ultra-early lines Rifor 1 ... 10 (F_6-7 Rico × Forlani Roberto k-42641) and Fori 1 ... 8 (k-65589 ... k-65596) (F4 Foton k-55696 × Rico). Their responses to a short 12-hour day were assessed. Vernalization conditions were 30 days at 3°C. The genetics of plant sensitivity to vernalization and photoperiods was studied using allele-specific primers for the genes Vrn-A1, Vrn-B1, Vrn-D1 and Ppd-D1.

Results and conclusions. In the Northwest of Russia, the period from seeding to heading for Rico plants was 39.9 ± 1.49 days, or 14.8 ± 1.22 days less than for the released commercial wheat cultivars. Among the 8400 wheat accessions, studied by the Wheat Genetic Resources Department of VIR in this area from 1948 to 2018, the shortest period from germination to heading was observed in the line Rico: 29 (28–30) days. The absence of response to vernalization in Rico, Fori and Rifor lines was determined by the dominant alleles Vrn-A1, Vrn-B1 and Vrn-D1. Photoperiodism in Rico and partially in Rifor was controlled by at least two genes: Ppd-D1 and Ppd-B1. In the F₂ population of Rico hybrids with 8 wheat accessions no transgression was observed beyond the limits of Rico‘s variation. The difference in the development rate between Rico and other wheat accessions is controlled by two or three non-allelic genes. Rifor lines can compete in productivity with commercialized wheat cultivars.

The genotype–environment interactions and the inheritance of quantitative traits in a hybrid combination between a seeded grapevine cultivar and a seedless one (Armira × Rusalka 1) have been studied. It has been found that the selection of valuable hybrid forms shall become more efficient when conducted according to the traits ‘flowering – berry softening’, ‘berry softening – technological maturity’, ‘cluster weight’, ‘weight of 100 berries’ and ‘acids’. Dominant gene interactions with the environment are characterized by significantly greater intensity in comparison to those of additive genes. Inheritance in F₁ progeny manifests very high values for the traits ‘budding’, ‘flowering’, ‘budding – flowering’, ‘flowering – berry softening’, ‘berry softening – technological maturity’, ‘berry length’. ‘berry width’, ‘weight of 100 berries’, ‘sugars’ and ‘acids’. According to the genetic stability of the dominant parameter interacting with the environment, a comparative evaluation can be made for each trait and, depending on the selection purpose, elite hybrid plants can be singled out, which possess a combination of the most important commercial traits.

Background. The problem of nucleus-plastid interactions is obviously of theoretical and practical importance. However, the lack of knowledge in this area of plant research is, for the most part, caused by difficulties in isolating the contribution of the plastome to the formation of complex morphophysiological traits from the total genotypic variability. The current study employed a convenient model for studying the fundamental problem of interaction between the nucleus and plastid genomes.

Materials and methods. The genetic model incorporated chlorophylldeficient sunflower mutant lines with extranuclear inheritance, developed on the genetic basis of a single inbred line. Various traits were measured in hybrids and parents, such as growth rate, plant height, inflorescence width, 1000 seed weight, chlorophyll content, seed oil content, etc.

Results and conclusion. While crossing extranuclear mutant lines with wild sunflower, a heterosis effect was observed for such traits as plant height and leaf size, regardless of the low chlorophyll content in F₁ hybrids. The growth rates of hybrids depended on the crossing combination: from an 86% excess (en:chlorina-7 maternal line) to complete absence of the heterosis effect (en:chlorina-6 maternal line). The results obtained witness to a significant contribution of cytogenes to the control over the trait. The inflorescence width and 1000 seed weight in all hybrid combinations (except en:chlorina-3) had similar quantitative characteristics as in the maternal mutant lines, and significantly exceeded the paternal form (wild sunflower). Consequently, plastid genes, along with nuclear ones, participate in the expression of these phenotypic traits. As for the oil content in seeds, no heterosis effect was observed in the hybrids.

Introduction. The V.S. Pustovoit All-Russian Research Institute of Oil Crops (VNIIMK) performs the breeding of interline rapeseed hybrids using the Ogura CMS. The program of interline winter rapeseed hybrid development was aimed at studying the efficiency of self-pollinated line breeding from population cultivars, assessing the impact of inbreeding depression on economically important traits, analyzing the changes in the lines’ traits after their transition to the sterile basis, and obtaining fertility restorer lines with an acceptable level of glucosinolate content in seeds.

Materials and methods. Intraspecific hybrids, cultivars developed at the Pustovoit Institute and those of foreign breeding were employed as parent material for the development of self-pollinated lines. Self-pollination of rapeseed plants was performed using spunbond isolators. Over 1000 plants were self-pollinated every year. Generations of self-pollinated lines S₁ –S₄ were planted on 2.25 m^₂ plots, and during the growth season their visual screening was undertaken to assess their morphobiological traits. Starting with S₅, the lines were evaluated for their yield on 7.5 m² plots.

Results. The inbreeding depression was found to not exceed 3–15% of the seed yield. The transition of the lines to sterile cytoplasm did not have any negative consequences. A series of experimental hybrids were developed, exceeding the reference cultivar ‘Loris’ in seed yield by 23–48%. New hybrid combinations also exceeded the reference in seed yield by 21–54%.

Introduction. Rapeseed is a facultative autogamous plant; its percentage of cross-pollination is 10–50%, so rapeseed breeding engages the line and population breeding methods as well as the development of hybrids and all innovative research approaches.

Material and methods. Among the main techniques used for the development of parent material and, eventually, cultivars at the Pustovoit Institute (VNIIMK) is the pedigree method (individual selection from intraspecific and interspecific hybrid populations, combined with inbreeding). Physical and chemical mutagenesis is also employed in rapeseed breeding at VNIIMK. The material with yellow-colored seed coat has been obtained by exposing rapeseed seeds to various doses of gamma rays (50, 100 and 150 kR). Seed treatment with chemical mutagens is primarily aimed at changing the fatty acid composition of oil.

Results. Breeding achievements for winter and spring rapeseed, registered by VNIIMK in the State Register of Breeding Achievements of the Russian Federation over the past 15 years, are highly productive line cultivars with a seed yield of 4–5 t/ha for winter rapeseed, and 2–3 t/ha for spring rapeseed. Promising experimental interline hybrids, significantly exceeding the reference in seed yield (by 1.61–2.26 t/ha), have been developed. Yellowseeded lines, which exceed the black-seeded reference cv. ‘Tavrion’ in seed yield by 0.08–0.15 t/ha, have been selected. We developed the material with an oleic acid level of 78.9–80.5%.

Background. Various types of mustard and its forms differ significantly from each other in a set of morphological, biological, biochemical and other economically important traits. Both brown and black mustard are in great demand.

Materials and methods. The study was conducted in 2009– 2018 on the brown mustard cultivar ‘Rosinka’ using the VNIIMK techniques. Promising cultivars of brown mustard (‘Zolushka’, ‘Nika’, ‘Yunona’) and black mustard (‘Niagara’) as well as source material with good breeding prospects were evaluated for their economic significance.

Results and discussion. Individual selection based on self-pollination in the seed production of brown mustard population cultivars was found to facilitate identification of high-yielding lines, promptly increase the yield of cultivars, isolate lines exceeding the initial population in oil yield, and obtain biotypes with unusual fatty acid composition. The best accessions demonstrated an increase of 1.0–2.9% in their oil content. Besides, the selected material had the yield at the same or higher level than the reference (on average, 3.22 t/ha). An increase of oil yield varied from 0.23 to 0.36 t/ha. The technique of recurrent individual selection of elite plants from interspecific hybrid populations with the use of selfpollination resulted in developing 3 brown mustard cultivars: ‘Zolushka’, ‘Nika’ and ‘Yunona’. One of the important trends in mustard breeding is the development of cultivars with a high content of allyl mustard oil. As a result of this work, a new brown mustard cultivar was developed (‘Gorlinka’). One of the representatives of the economically important Brassicaceae family is the black mustard. Its new cultivar ‘Niagara’ was developed by recurrent individual selection from accession k-2632 preserved in the collection of the Vavilov Institute of Plant Genetic Resources (VIR). In competitive trials ‘Niagara’ demonstrated an average yield at the level of 1.5–1.7 t/ha, and the oil content in seeds of 37.0–40.0%. Cv. ‘Niagara’ has a short growing season.

A study of the Mongolian flora and a survey of the herbarium collections of the Institute of General and Experimental Biology, Mongolian Academy of Sciences, conducted in 2019, provided new information on the geographical distribution of Amaranthus retroflexus (Amaranthaceae, Chenopodiaceae s.l.) and Brassica juncea (Cruciferae, Brassicaceae) in Mongolia.

Background. Ornamental peaches are flowering trees with petals ranging in color from white and pale pink to purplered. Because peach suffers from fungal infections, Prunus mira Koehne is often used in breeding programs as a donor of resistance. It also impacts on other traits, including flower color. The aim of this work was to study the composition of flavonoid pigments in the flowers of parent plants and new ornamental peach cultivars originated from P. mira.

Objects and methods. Four new cultivars developed at the Nikita Botanical Gardens and their parental forms – P. mira and 4 cultivars with the P. persica morphotype – were included in the study. Pigments were extracted with acidified ethyl alcohol from fresh petals and identified by HPLC analysis.

Results. Twelve glycosides of cyanidin and peonidin in different combinations and 8 glycosides of kaempferol and quercetin were found in the petal samples. Among colored plants, the highest amount of flavonols (114 mg g-1) and the lowest amount of anthocyanins (0.46 mg g-1) were found in P. mira petals. Anthocyanins predominate in cultivars with purple-red petals (16 mg g-1). Much more flavonols (55–88 mg g-1) and little anthocyanins (1.2–3.4 mg g-1) were accumulated in the purple-pink flowers of hybrid cultivars. This trend persisted in the cultivars from crosses with a white-flowered parent. Conclusion. The ratio of anthocyanins and flavonols in the peach flowers depends on the plant species and determines the petals’ intermediate colors and half-tones. Using P. mira in breeding programs provides opportunities for the development of cultivars with new shades of flower color.

In recent years, an increased interest in emmer wheat (Triticum dicoccon Schrank) has been observed, due to the dietary value of its grain, which is used for making highquality cereal products. The main disadvantages of this crop are a relatively low yield, if compared with other wheat species, a brittle ear, and problems with grain threshability (filmy kernels are threshed out of the ear together with the chaff). Thus, developing hulless cultivars of emmer is at present an urgent task. Constant lines of naked emmer wheat, which make up the described subspecies, served as the material for this research, including four lines developed at VIR by A. F. Merezhko and seven by V. D. Kobylyansky. The wheat produced from interspecific crosses between different varieties of the hulless T. durum Desf. and various local forms of the hulled T. dicoccon (Schrank) Schuebl. has deserved the rank of subspecies (T. dicoccon (Schrank) Schuebl. subsp. nudicoccon Kobyl. et Smekal.). The obtained hulless wheat demonstrates morphological features characteristic of T. dicoccon: its ear is flat, there are two grains in the spikelet, etc., while its kernels are easily separated from chaff.

Background. Analyzing the adaptive potential of cultivated barley with the aim of using new genotypes selected and developed in the process of work is a priority trend in scientific research. The Ethiopian barleys adapted to a variety of soil and climate conditions are characterized by many valuable biological and agronomic traits. Of particular value are genotypes that combine resistance to harmful organisms and environmental stressors.

Materials and methods. The collection accessions of Ethiopian barley possessing powdery mildew resistance were studied for tolerance to adverse edaphic factors (chloride salinity and high content of toxic aluminum ions in the soil). Resistance to abiotic stressors was assessed in laboratory experiments. In the study of salt tolerance, a ‘roll-based’ assessment technique was used, which takes into account the inhibition of root growth under salt (NaCl) stress conditions, compared with the reference conditions without salinization. Aluminum sensitivity of barley accessions was diagnosed in the early stages of plant development using the root test.

Results and conclusions. A polymorphism of Ethiopian barleys for resistance to adverse edaphic factors was revealed. Twentyone new sources of barley resistance to toxic aluminum ions were identified, of which accessions k-8552 and k-22933 were classified as highly resistant. Accessions k-17554, k-19975, k-20029, k-20048, k-22752, k-23450 and k-25009 proved resistant to soil salinization. Barley accessions k-17554, k-22752 and k-25009 were characterized by complex resistance to powdery mildew, toxic aluminum ions, and chloride soil salinity.

Background. Despite the great efforts made by breeders, late blight remains a paramount cause of significant potato harvest losses. Introgression of various resistance genes from wild Solanum L. species is the main method to increase the resistance in potato cultivars. Field resistance is considered to be more durable than those induced by the action of single R genes. To this end, resistance sources should be selected from а wide range of species under severe natural infection.

Material and methods. As the material for evaluation, 1141 accessions of 99 wild potato species belonging to 15 taxonomic series according to the system of J. Hawkes were used. Each accession was assessed for 3–5 years. A 1–9 point scale was employed to score the damage of plants every week starting from the first symptoms of the disease, where 9 meant the absence of any symptoms, and 1 the entirely damaged plant. The plants scoring 6 to 9 points were considered resistant.

Results and conclusions. As a result of the long-term field observations, wild potato species, represented in the current evaluation by numerous accessions, were characterized for foliar resistance to late blight; individual introductions resistant to late blight were also identified. Some of those studied in the 1980s showed high resistance in the end of the 1990s through the 2000s. The highest percentage of resistant accessions/species was identified among the species with areas of distribution in Mexico. A group of Central American species and large part of species with areas of distribution in South America expressed high level of interspecific polymorphism in foliar resistance to late blight.

Background. Powdery mildew of bread wheat caused by the fungus Blumeria graminis (DC.) E.O. Speer f. sp. tritici Em. Marchal is a widespread foliar disease of wheat in regions with cool and wet climate. It infects the foliage, stem and spike of the wheat host and causes yield reduction. Breeding for resistance is the economical way to control this disease. The object of this work was to analyze spring cultivars of wheat (Triticum aestivum L.) for powdery mildew resistance and some productivity indicators.

Materials and methods. The study involved 150 European spring bread wheat cultivars whose resistance to the fungus was assessed at the seedling, heading and flowering phases of plant development. The population of the fungus manifested virulence to Pm1, Pm2, Pm3a-d, Pm4a-b, Pm5a, Pm6, Pm7, Pm8, Pm9, Pm16 and Pm19, and avirulence to Pm12. The damage to seedlings was evaluated using the scale from 0 (no damage) to 4 (abundant pustules). Resistance of the adult plants was analyzed according to the scale from 9 (no damage) to 1 (abundant pustules).

Results and conclusions. Of the 150 cultivars, resistance at the seedling stage was shown by 12,7%, and at the adult stage by 20,1%. The cultivars ‘Dacke’, ‘SW Estrad’, ‘Sparrow’ and ‘Aranka’ were resistant in all phases of plant growth. ‘Naxos’ was characterized by a short period from seedlings to heading. The cultivars ‘Aranka’, ‘Zuzana’, ‘Septima’, ‘Tercia’ and ‘Sparrow’ had short stems, while ‘Torka’, ‘Sparrow’ and ‘Pasteur’ – large grains.

Spring bread wheat is the most important cereal crop, cultivated under various climatic conditions and on different latitudes. Modern molecular genetic studies of wheat are aimed at investigating the crop’s genetic potential. By now, molecular markers have been developed to identify alleles of the Vrn (vernalization response) and Ppd (photoperiod response) genes. Vrn genes are responsible for crop development rate regulation and crop yield structure. Ppd genes determine the response of plants to the length of the day, that is, the timing of flowering and the beginning of heading in plants under different cultivation conditions. The use of diagnostic DNA markers made it possible to analyze the presence of allelic combinations of the Vrn and Ppd genes in local and commercial wheat varieties from Europe, Asia, North and South Americas, Africa and Australia. This review summarizes the results of studies on the distribution of alleles of Vrn and Ppd genes in wheat breeding material over different geographical areas of its cultivation. For example, the dominant Vrn-A1a allele was found in 62% of European varieties; 52% of the studied Turkish wheat varieties carried dominant Vrn-B1 alleles. A dominant Vrn-D1 was found in 61% of Pakistani wheat accessions. Vrn-D1 is present in 41.9% of the studied varieties of Chinese wheat. Higher incidence of Ppd-D1A is typical for West European varieties. A Ppd-D1a allele was found in 58.6% of varieties preserved in the Turkish wheat collection, with a 60% frequency of this allele in commercial cultivars. Among local Afghan varieties, 97% are sensitive to photoperiod (carriers of Ppd-D1b); they are distributed throughout the country without much dependence on agroecological zones. All Pakistani varieties are insensitive to photoperiod (carriers of Ppd-D1a). In China, the highest incidence of the Ppd-D1a allele was observed in zone VII (87.5% of varieties).

Possible causes of melanosis in millet have been studied for a long time, and numerous efforts have been made to breed resistant cultivars, but still there are no sources of high resistance to this disease. The purpose of this article is to provide an overview of the most important results of research into the nature of melanosis in millet, a disease without outward manifestation on plants or seeds, and search for ways to reduce its harmfulness. Although the disease’s infectious nature has been confirmed by all researchers, no one has succeeded in identifying the causative agent of melanosis. It is assumed that melanosis may be provoked by both bacteria and fungi as well as through their complex effect on a plant. Weather conditions conducive to a spread of infection have not been identified either. According to some reports, dry and warm weather increases the risk of infection and spreading of the disease; according to others, more humid and warm conditions are to blame. A possible effect of millet grain shape on the level of disease manifestation has not been clearly explained, but there is evidence that the degree of floral scale closeness and thickness as well as the grain size do enhance mechanical protection of seed from infection. When floral scales are tightly closed, coarsehulled fine grains are as much protected from exposures as possible, which may add to the plant’s defense against the infection. Selecting plants with better developed grain-enclosing scales would help to breed proso millet cultivars resistant to melanosis. The infection can be transmitted by insects, wind or rain from any crop fields infested with the microflora that causes the disease. Its causative agents are specific to a definite area of millet cultivation, which is determined by the temperature regime and indirectly confirmed by conflicting data concerning the effect of air temperature and precipitation on the development of melanosis. The duration of the growing season, in its turn, can also have an impact on the development of damage under the husk of millet grain. Early-ripening millet forms are more resistant to the disease.