Conservation of the world’s plant genetic resources is one of the most significant and relevant problems of mankind. At Krymsk Experimental Breeding Station of VIR, where the largest stone fruit plant genetic diversity in Russia is assembled (more than 5 thousand genotypes: cultivars and species, wild forms, distant hybrids and polyploids), a collection maintenance technology of ‘border hedging’ has been developed and successfully used. This method makes it quite economical (in terms of space reduction, simplification of the system of care for the storage garden, and decreasing the use of chemical protection agents) to maintain a large number of live accessions ex situ. The border hedging technology is based on a propagule nursery system that enables plants to grow longer than in conventional gardens, constantly keeping them in a state of active growth. The basic elements of this technology are dense arrangement of plants (intervals for high-growing plants: 4.0–5.0 m between rows, and 1.0–1.5 m in a row; for low-growing ones: 2.5 m between rows, and 0.5–1.0 m in a row) and annual pruning of shoots at a height of 1.0–1.2 m. Years of experience in using a denser planting pattern for collection garden maintenance helped to identify a number of most significant factors in this system, which make up the scientific basis of the technology for optimally efficient preservation of genotypes and their genetic compliance (representativeness). Among them are biological features of the in situ plant growth habit, including vigor, selection of rootstock or decision on own-root cultivation, layout of the plot, and maintenance system. If it is necessary to study the accessions in the garden where they are preserved in order to make their initial evaluation (approbation, morphological description, study of crop structure, biochemical or biotechnological assessment, analysis of resistance to biotic and abiotic stressors), the plants should not be pruned for 1–2 years. Upon completion of these works, the trees are coppiced again.

An algorithm has been developed at Krymsk Experiment Station of VIR to build up and maintain the work with the existing and future collections of berry crops. It incorporates both practical and theoretical activities into the management system, whose ultimate goal is the improvement of cultivars. The studies to optimize the maintenance of blackberry and dewberry collection orchards of VIR resulted in the development of a support-free cultivation technique for trailing blackberry (northern dewberry) accessions. It was proposed to plant them in rows, earlier mulched with a black polymer film resistant to photodecomposition and high solar radiation, one-meter wide, with a pipe buried underneath it for drip irrigation and fertigation through drippers arranged at intervals of 1.1 m. The edges of the polymer film are proposed to be pinned to the ground with metal studs or sprinkled with earth to avoid disturbances of the mulch integrity. The planting pattern for seedlings needs to be denser than the conventional one (with trellises) and is prearranged by digging holes in the mulching film, up to 10 cm in diameter, at intervals of 1.1 m in a row, so that a dripper is placed above the root system. The space between rows is 1.0–1.1 m. In the proposed method, regrown shoots are pruned during the growing season at a height of 80–90 cm. This operation enables fruit buds to develop next year on these shortened shoots and second-order shoots formed upon them, which will also be pruned or nipped at a height of 30–40 cm. After the end of fruiting, such shoots are removed, and those regrown at the base of the shrub are shortened in the same manner as above. This in vivo maintenance technology for trailing blackberry or dewberry accessions preserved at Krymsk Station of VIR was duly tested, and the trials showed its higher efficiency compared with the reference technique involving trellising of preserved plants. When a black polymer film is used at a plantation for mulching, there is no need for herbicides against weeds, which alleviates the pressure of chemicals on the environment and contributes to the greening of an agrocenosis.

Background. Plant genetic resources (PGR) conservation is an indispensable condition for ensuring the country’s economic and environmental security. The most important component of the PGR status assessment is the study of crop wild relatives in a particular region. Within the framework of the work on inventorying crop wild relatives (CWR) in the regions of Russia, an inventory of CWR was for the first time made for Magadan Province, Far East region of Russia, to identify plant taxa that are prioritized for conservation and monitoring of their status in natural phytocenoses.

Materials and methods. The material for the present research was taken from the data published on the vegetation of the studied region. Taxonomic analysis of CWR was performed using conventional floristic methods. In order to select priority species for conservation, the guidelines for PGR conservation adapted for Russia were used.

Results and conclusions. A list of 232 CWR species belonging to 62 genera of 21 families has been compiled; it encompasses nearly 20% of the entire regional flora. The indigenous part of CWR amounts to ca. 60%, while the adventive part includes 40% of the total CWR number. Analysis of distribution of CWR species over the studied area showed that the greatest diversity of CWR species (81%) is concentrated in the Okhotsky floristic district. As a result of the analysis, 76 species occurring in Magadan Province were identified for prioritized in situ conservation.

The use of adaptable fruit and berry cultivars significantly increases the environmental sustainability of horticulture. In 2014–2018, the assortment of plum in the Urals was evaluated using the parameters of productivity, environmental plasticity and stability under the conditions of Chelyabinsk Province. The analysis of environmental plasticity and stability helped to identify adaptable cultivars of Chinese plum (Prúnus salicina L.): ‘Altayskaya yubileynaya’ and ‘Uralskaya zolotistaya’. Plastic plum cultivars included cv. ‘Uralskaya zolotistaya’ (yield: 5.62 t/ha; bi = 1.10; Si2 = 25.7), ‘Uralskaya serebristaya’ (5.53 t/ha; 1.16; 21.3) and ‘Manchzhurskaya krasavitsa’ (5.53 t/ha; 1.21; 33.9); their productivity varied in accordance with changes in environmental conditions. Intensive-type cultivars with high responsiveness to the improvement of growing conditions (bi significantly higher than 1) were cvs. ‘Uvelskaya’ (5.62 t/ha; 1.46; 26.8) and ‘Krasnoselskaya’ (5.04 t/ha; 1.35; 45.7). Cv. ‘Zhemchuzhina Urala’ (4.65 t/ha; 0.05; 22.8) belongs to the cultivars with low plasticity (the bi value close to zero); it is characterized by a weak response to a change in environmental conditions. Cv. ‘Altayskaya yubileynaya’ produces the highest yield (6.16 t/ha) due to its plasticity (bi = 0.91), but has low stability (Si2 = 102.5), while cv. ‘Shershnevskaya’ secures rather high productivity (5.23 tons per hectare) due to high stability (Si2 = 32.7) and medium responsiveness to changes in environmental conditions (bi = 0.75).

Background. The primary specialization branches of agriculture in Tyumen Province are plant production and dairy farming, with cattle husbandry being lately introduced, which implies a demand for feed crops, in particular perennial grasses, among which smooth brome (Bromopsis inermis (Leyss.) Holub) is the most widespread. With such demand in mind, the Research Institute of Agriculture for the Northern Trans-Urals has been engaged in studying pasture grasses in order to find and develop new lines adaptable to local conditions.

The purpose of the study was to examine the dynamics in forage productivity of smooth brome for a 4-year period of utilization to produce varietal characteristics of the breeding material.

Materials and methods. Observations were carried out in 2014–2017 in a competitive testing nursery (CTN) set up for smooth brome plants sown in 2013. Cultivars and breeding lines, 17 accessions in total, were the material of the study. Their herbage yield was analyzed for 4 years when the grass stand was utilized (5 years of life). The accessions were classified into productivity groups and according to their utilization possibilities. 

Results and conclusions. Over the 4-year period of utilization in the CTN, the smooth brome accessions were distributed into 6 productivity groups according to the amounts of herbage collected – from 8 to 30 t/ha (with an interval of 4 t/ha). In the 1st and 2nd years of testing, the yield was in the range of 21.3–30 t/ha; in the 3rd and 4th years, there was a decrease to 8.0–19.6 t/ha. Comparison of the data for each of the accessions showed that all of them reduced their productivity to varying degrees – from 32 to 72%, the evidence of a significant difference between them. Thus, it became possible to divide them into 3 groups, reflecting their advantages in the context of targeted utilization in the environments of Tyumen Province: I. Haymaking group: accessions with the highest herbage yield in the 1st year of utilization (28–30 t/ha) and its significant decrease by 68–72% to the 4th year of utilization may be suitable for short-term use in field crop rotations (the reference ‘Langepas’; 7-1-67; 10-1-15; 19-3-37). II. Haymakinggrazing group: accessions with medium productivity in the 1st year of utilization (24–27 t/ha) and its moderate reduction by 42–64% to the 4th year of utilization can be used in forage rotations for 5–7 years (‘Argonavt’; ‘Ingair’; ‘Stepasha’; ‘Yarilo’; 7-1-54; 15-2-63; 4-4-17; 7-4-49; 4-2-20). III. Grazing group: accessions with low productivity in the 1st year of utilization (20–23 t/ha) and its slow decline by 39–50% to the 4th year of utilization are promising for long-term exploitation when pastures are established, or special-purpose lawns are sown, or disturbed lands are recultivated (‘Sverdlovsk 38’; ‘Zauralets’; 5-3-8; 1-11).

Background. Oils of hemp and cotton presently have reduced retail trade offer in Russia, but are widely produced and used. Industrial hemp is still cultivated and processed domestically. In the 1950s, industrial cotton was cultivated on a hundred thousand hectares in the country, and now there are signs of its restored growing. Both crops have the ability to restore the raw material base to produce textile fibers, seed and oil as well as the potential to improve functional food production, because they contain functional food ingredients in their oil capable of reducing human nutrition disorder risks, preventing or restoring nutrient deficiencies, preserving and improving health.

Materials and methods. Unsaturated and polyunsaturated fatty acids’ profiles of hempseed (Cannabis sativa L.) and cottonseed (Gossypium hirsutum L., G. herbaceum L., G. barbadense L.) oils were evaluated. Seeds were grown respectively under the conditions of the Russian North-West (hemp) and Adler District, Krasnodar Territory (cotton). The PUFA profile was measured using gas chromatography with mass spectrometry equipment (Agilent 6850, USA). All data were calculated using the UniChrom software.

Results and conclusions. The content of the omega-6 linoleic acid in hemp accessions reached 64.2%; omega-3 alpha-linolenic acid, 27.1%; monounsaturated oleic acid, 14.0%. The sum of unsaturated acids was 94.2%; and that of polyunsaturated ones, 87.2%. Compared with hemp oil, cotton oil had a lesser sum of polyunsaturated (maximum 58.0%) acids, while its unsaturated acids were up to 79.0%. Oleic acid was found to reach 22.7% in cottonseed oil. Industrial cultivation of hemp and cotton in Russia need not be limited to textile fiber production, but may serve as a potential base of vegetable oils and food; just because of their PUFA contents, it is promising for the production of functional food ingredients, which have health benefits in reducing the risk of cancer and cardiovascular diseases, lowering the HDL cholesterol levels, and relaxing the smooth muscle cells in arteries, thus increasing the blood flow. Seed cake may be valuable addition to animal feed rations as well. As a result of the evaluations, valuable accessions (cultivars and lines) of hemp and cotton were identified. Although the selected accessions are not the products of previous breeding efforts aimed at the PUFA content improvement, they are promising source materials for the development of new cultivars with seeds enriched with compounds or sets of compounds that provide a beneficial effect on human health when included in the composition of food products (functional food ingredients). 

Background. An important trend in modern breeding of common beans is to improve the quality of grain. High protein content in seeds is one of the most important indicators of the nutritional value of beans. Searching for high-protein accessions, identifying sources of high protein content, and using them in the breeding process, while developing new cultivars, still remain relevant. The aims of our research included the identification of variability patterns for protein content in accessions of different origin, characterization of cultivars, and description of their morphological and economic traits.

Materials and methods. Presented here are the results of biochemical screening of 166 common bean (Phaseolus vulgaris L.) accessions of various ecogeographic origin, added to the VIR collection in 2005–2016. Field study of economically valuable traits was carried out according to VIR’s techniques. The protein content in seeds was measured in the Biochemistry and Molecular Biology Department at VIR using Kjeldahl method. Mathematical data processing (correlation analysis and single-factor analysis of variance) was performed using Statistica 7.0 software (StatSoft, Inc., USA).

Results and conclusions. As a result of the assessment, 12 sources of high protein content in seeds (> 28% annually) were identified and described. The average value of the trait differed depending on the country of origin, genotype and year of study. The correlation analysis failed to find general regularities (strong stable interrelations) between the protein content in seeds and morphological, economically valuable traits. The values of correlation coefficients were unstable over the years of study. Weak links between the protein content and the genotype (r = 0.25) or the year of reproduction (r = 0.24) were identified. Significant relationships between protein content, morphological and economically valuable traits were not found. Seed protein content, according to the results of the single-factor analysis of variance, largely depended on the genetic properties of plants (effect size is 70.1%), and, to a smaller extent, on the year of reproduction (14.5%) and origin (17.5%).

Background. Abiotic stressors, such as prolonged dry conditions, oversupply or lack of moisture, frost, etc., are spontaneous, and their impact causes significant damage to plants. This is also true for the common and leafless morphotypes of vegetable pea, which are most widely used in large-scale crop production.

Objectives. Eleven cultivars with leaves of  the usual type (common morphotype) and 6 semi-leafless ones (leafless morphotype) were studied.

Materials and methods. The experiments were performed on the breeding fields of Krymsk Experiment Breeding Station of VIR (Krasnodar Territory, 2015–2016). The plot area was 10 m2. There were 3 replications. Dry matter content was measured by drying the aerial parts of plants (axial organs, foliar apparatus [leaf, stipules], flowers, unripe beans, pod valves, grain) to constant dry matter at 105°C. Dry matter contents were compared using the t-test. Multifactorial analysis of variance (MANOVA, LSD test) was used to assess the yield of vegetable pea cultivars.

Results. Vegetable pea plants are subject to the negative effect of abiotic stressors. With excessive moisture in the initial period of growth, there was a decrease in the accumulation of dry matter in plants. A similar effect is exerted by long absence of precipitation during the growth period of vegetable pea plants from the phase of 2–3 leaves to technical ripeness. The effect of weather conditions during cultivation on the yield of vegetable peas was estimated at 13.3%; and the interaction of the genotype٭environment factors, at 33.3%.

Conclusion. No significant differences were observed between the groups of common leafy cultivars and semi-leafless ones in the content of dry matter in the aboveground biomass of plants and the yield. During the two years of research, the cultivars that exceeded the reference in yield were identified: ‘Prima’ (i-155213, Russia) and ‘Ambassador’ (k-9946, Germany), both belonging to the common morphotype.

Background. High yield is one of the main requirements for modern black currant cultivars. It depends on many factors, but is always linked to self-fertility. Highly selffertile cultivars are of particular importance in areas with unfavorable weather conditions during flowering, because they are able to provide high yields even in single-cultivar plantings. In this regard, it is very important to study selffertility of cultivars in order to identify those with the highest level of this character for use in breeding and large-scale cultivation.

Materials and methods. The study of selffertility was carried out at Pushkin and Pavlovsk Laboratories of VIR in 2014–2017. Fifty-seven black currant cultivars of different genetic and ecogeographic origin were the material of the research. The degree of self-fertility was measured by conventional techniques in 3 variants of pollination: 1) natural self-pollination; 2) artificial self-pollination; and 3) free pollination. Statistical data processing was performed using Microsoft Excel and the guidelines by B. A. Dospekhov.

Results and conclusions. Highly self-fertile cultivars were identified, which may be recommended for breeders as sources of this trait: ‘Navlya’ (k-42228), ‘Dobrynya’ (k-42121), ‘Golubichka’ (k-32624), ‘Golosievsky velikan’ (k-44176), ‘Valentina’ (k-15631A), ‘Kozatskaya’ (k-44187), ‘Arapka’ (к-44175), ‘Kanakhama’ (k-44197) and ‘Fat’ (k-42509). High yield in the Northwest of Russia can be secured by cultivars that combine high self-fertility with large fruit size: ‘Valentina’ (k-15631A), ‘Vernisazh’ (k-43126), ‘Garmoniya’ (k-40677), ‘Dobrynya’ (k-42121), ‘Desertnaya Ogoltsovoy’(k-45670), ‘Joninai’ (k-43124), ‘Kanakhama’ (k-44197), ‘Karri (k-44172), ‘Mila’ (k-40673), ‘Sevchanka’(k-45551), ‘Sofievskaya’(k-43131), ‘Talisman’ (k-44183), ‘Yubileinaya Kopanya’ (k-44189), ‘Shalunya’(k-41988), and accession 2780-20-33 (k-15575A). It is shown that free pollination and artificial self-pollination
provide a positive impact on the fruit setting level, fruit weight and seed productivity. Natural autogamy, on the contrary, tends to decrease the weight of berries and the number of seeds in them.

Background. Resistance to lodging is a factor that significantly affects the yield of barley under the conditions of irrigated agriculture and intensive type of farming. Barley resistance to lodging depends on many features, among which the length of the plant stem is more important.

Materials and methods. In the southern planar area of Dagestan, from 1993 till 2008, a research was conducted on the intraspecific diversity of cultivated barley (Hordeum vulgare L.) belonging to different ecogeographic groups, and growth types (2,021 accessions). The F1, F2 and F3 hybrids from crosses of the long-stemmed cultivar ‘Sonet’ with semi-dwarf forms were also studied. The selected recombinant lines were evaluated for their productivity and resistance to frit fly (Oscinella frit L.).

Results and conclusions. Wide variability (55–155 cm) of cultivated barley in plant height was observed. Under irrigation in the southern Dagestan, the optimum height of plants, providing high resistance to lodging, was 100–115 cm. A number of semidwarf cultivars were identified; among them, ‘Camincent’ (k-30374, Estonia), ‘Pyramid’ (k-30564, France), ‘Ramos’ (k-30315, Moscow Province) and ‘Jo 1632’ (k-30459, Finland) were the most interesting for their set of traits. The short stem of these cultivars is controlled by recessive alleles of genes. We selected productive lines that significantly exceeded their parental forms in grain weight per area unit and resistance to frit fly: L 15/4 (F6 Sonet × Camincent) and L 16/12 (F6 Sonet × Pyramid). These lines can be used to breed lodging-resistant large-grain barley cultivars for cultivation on irrigated lands.

Background. Pumpkin is an important food, feed and medicinal crop. It is widely used by national cuisines in many countries and utilized as raw material for canning industry and in pharmacy to prepare drugs. The Kuban Experiment Station of VIR, where the collection of pumpkin genetic resources is maintained and regenerated for long-term storage in the genebank, conducts comprehensive research work to analyze the genetic diversity of pumpkin accessions and disclose the potential of its hereditary variation.

Objective. The aim of this study was to screen various species from the global pumpkin collection and identify sources of traits valuable for breeders in order to develop promising cultivars and hybrids.

Materials and methods. The pumpkin collection was studied and the breeding work was performed using the guidelines worked out by VIR’s scientists. The work included botanical description, study of variability and inheritance of traits, hybridization, inbreeding, mutagenesis, and different selection techniques (individual, group, individual/ family, and mass selection). In the first stages of the study, inbreeding was employed to select best plants from the collection in order to set up a trait-specific collection and incorporate its accessions into the hybridization process. Self-pollination was used
for several years to obtain self-pollinated lines, sufficiently uniform in the selected trait. The hybrid progenies from crosses between parental forms were analyzed to throw light on the inheritance of major traits and their genetic control. The accessions were assessed for their earliness, productivity and quality. Evaluation of disease resistance was carried out in the field under natural infection pressure.

Results and discussion. Targeted breeding efforts resulted in releasing cultivars of Cucurbita pepo L., C. maxima Duch. and C. moschata Duch. ex. Poir. having different maturation schedules and approved for cultivation in various regions of Russia: ‘Kustovaya oranzhevaya’, ‘Lechebnaya’, ‘Kustovaya zolotaya’, ‘Malyshka’, ‘Matreshka’, ‘Krasavitsa’, Zimnyaya sladkaya’, ‘Zhemchuzhina’, ‘Yantarnaya’ and ‘Mariya’. These cultivars are in demand among both agricultural producers and individual growers. New sources of valuable morphobiological and agronomic characters have been identified as useful for modern plant breeding trends: KL 625, ZhZM 692, L-180, L-193, KPL 168, KL 568 and KL 570. New bushy lines of C. maxima and C. moschata selected from cultivar and hybrid populations are now tested in an elite test nursery in order to submit the best of them to the State Variety Trials. 

Background. The primary task of plant breeding is to develop and introduce into production two-row mid-season barley cultivars for feed and food purposes, capable of generating a high and high-quality grain yield.

The purpose of the study is to characterize the new two-row fodder spring barley cultivar ‘Omsky 101’ (bred at Omsk Agrarian Scientific Center) according to its grain quality, yield and resistance to a set of diseases.

Materials and methods. The experimental part of the work was carried out from 2013 through 2018 on the experimental fields of Omsk Agrarian Scientific Center, located in the southern forest-steppe and steppe zones. The area of the plot was 10 m2; there were 4 replications. The seeding rate was 4 million viable seeds per 1 ha. Agricultural practice in the experiment was conventional for the West Siberian region. Mathematical data processing complied with B. A. Dospekhov’s guidelines.

Results. In terms of productivity, the new promising cv. ‘Omsky 101’ is a high-yielding variety; on average, over the period of research, its yield significantly exceeded the level of the reference cv. ‘Omsky 95’ both in the southern forest-steppe zone (+0.55 t/ha) and in the steppe zone (+0.38 t/ha). The increase over cv. ‘Omsky 100’ was 0.29 and 0.59 t/ha when sown over autumn plowing and fallow, respectively. When compared with the reference ‘Omsky 95’, ‘Omsky 101’ showed a gain in the weight of 1000 grains (+5.3 g), grain unit weight (+44.0 g/l), and grain uniformity (+12.4%). Also, when compared with both the reference and ‘Omsky 100’, there was an increased content of protein (+1.0 and +0.9%, respectively) and starch (+1.3 and +1.5%, respectively) in grain. During the period of study, according to the maximum damage scores with various smut species, ‘Omsky 101’ showed low rates of susceptibility to false loose smut (3.5% on average) and covered smut (5.0%), which is lower than the reference and level with cv. ‘Omsky 100’. Loose smut virulence rate was medium (23.1%), which is level with the reference but exceeds ‘Omsky 100’.

Conclusion. The new promising cultivar ‘Omsky 101’ is high-yielding, of high quality, and resistant to smut species. The cultivar has been submitted to State Variety Trials in the Ural (9), West Siberian (10) and East Siberian (11) regions.

Background. When studying the collection of watermelon, it is important to disclose its genetic potential by identifying spontaneous mutations, using its accessions in crosses, and analyzing inheritance of its main traits in hybrids. One of the priorities in watermelon breeding is to develop and produce genetic sources of bushy and short-vine forms with stable manifestation of their morpho-biological characters under various environmental conditions.

Material and methods. Accessions from the watermelon collection (local landraces, commercialized and promising cultivars, hybrids and lines obtained in the process of work) of diverse ecogeographic groups served as the material for this research. Description of morphological characters and assessment of economically useful ones were based on the guidelines for studying and maintaining the cucurbit collection and the guidelines for cucurbit crop breeding, both developed by VIR.

Results. Variability and inheritance of the bushiness and short vine characters were studied in watermelon accessions according to the features of their growth and development. The habitus of the bushy forms is shaped by the length of stems (0.8– 1.2 m) and very short (2–3 cm) internodes. Short-vine plant stems are 1.3–1.5 m long. Short-vine plants in the early period of development distinctly stand out for their compact bush, if compared with long-vine forms. Short vines are developed due to short internodes (4–5 cm) and a smaller number of lateral shoots.

Conclusion. Many years of studying the watermelon collection in the field resulted in identification of promising genetic sources for the breeding of bushy and short-vine cultivars: bushy dissected-leaf lines (KRL) – KRL 694, KRL 656, KRL 376 and KRL 394; bushy entire-leaf lines (KTsL) – KTsL 760/13; yellow-green bushy dissectedleaf lines (ZhZKRL) – ZhZKRL; short-vine watermelon lines (KPL) – KPL 774 and KPL 368. The developed lines differ in morpho-biological and economically useful characters (yield,
fruit quality, growing season duration, etc.). They possess resistance to diseases (fusarium wilt and anthracnose) and environmental stressors. The lines are offered for use in the breeding of new bushy and short-vine cultivars and improvement of the existing ones, with various combinations of morpho-biological and economic traits. Brief descriptions of main economically valuable characters of the breeding lines are presented.

Background. Resistance to the effects of plant biotic stressors is determined by a set of factors. Among them, the leading protective role is often assigned to the physiological and biochemical characteristics of the surface tissues. However, one cannot ignore the specificity of the microstructural organization of the plant surface, since the nature of interactions in phytopathogenic organisms is more complex than the chemical impact. Meanwhile, the information accumulated to date about the structure of the surface tissues of the vegetative and reproductive organs of plants, and the interface of mycobiota, is fragmentary.

Objective. Mature leaves and fruits taken from representatives of the subfamily Maloideae Werber (Malus domestica Borkh., Pyrus communis L., Cydonia oblonga Mill. and Mespilus germanica L.) were selected for the study.

Materials and methods. Samples for the research were taken from the middle part of the crown of model trees in 3 replications. In recent years, scanning electron microscopy (SEM) with cryofixation is considered the most promising technique and is used to analyze the surface of biological organisms and identification of species. It is particularly informative in the case of organisms with complex surface micromorphology and for studying the biodiversity of pathogens. However, in this work we combined the methods of light, electron (SEM, TEM) and confocal microscopy. The samples were also studied using phytopathological and histochemical techniques. Condensed polyphenols were detected using K2Cr2O7 and FeCl3 as well as 4-(Dimethylamino)cinnamaldehyde (DMACA, Sigma-Aldrich).

Results. On the basis of the obtained phytopathological materials and published data an overview of fungal diseases afflicting leaves and fruits of M. domestica, P. communis, C. oblonga and M. germanica was made. It has been established that a common feature of the Maloideae fruits is the accumulation of condensed polyphenols, which play an important protective role against biotic stressors, in the cells of the pericarp’s outer tissues. Anatomical and morphological characteristics of passive immunity, or horizontal resistance to fungal pathogens, include the specific nature of waxy and cuticular deposits, features of the formation of cuticular folds and peristomatic rings in the stomata area and microstrands at the base of trichomes, thickness of the cuticle and cork tissue, and the development of lenticels on fruits.

Conclusion. The studied model plants suffer from a sufficiently wide range of diseases with different etiologies; among them, the most widespread and harmful are mycoses. In view of this, their resistance to fungal pathogens correlates with the specificity of the leaf and fruit surface microstructure and the content of phenolic substances (polyphenols) in the cells of the pericarp’s surface tissues.

Background. Currently, the most widespread and harmful disease of cucumber is downy mildew. In this regard, a vitally important trend in cucumber breeding is the development of new cultivars, more resistant to downy mildew, for cultivation in different regions. Solution to this problem requires searching for donors of resistance for use in breeding practice.

Materials and methods. The studies were conducted at Volgograd Experiment Station of VIR using conventional methods. The material for the screening was the collection of cucumber genetic resources held by VIR.

Results and conclusions. During 32 years of work, 2873 cucumber accessions from VIR’s holdings were screened. As a result, 57 accessions with resistance or relative resistance to downy mildew were identified, i. e. 2.0% of the total number studied. Immune accessions were not found. Among the selected accessions, those with the highest yield are noteworthy: landraces from Azerbaijan (temp. k-3999 and temp. k-4004) as well as the cultivars from China ‘Zungsungerum-oi’ (temp. k-3701), ‘Tianin mini cucumber’ (k-4490), ‘Tian Uzin Yao No. 5’ (temp. k-3840) and ‘Tian Uzin Yang No. 6’ (temp. k-3841). Of the resistant and relatively resistant accessions, 76% were from Southeast Asia. During the years of study, 23 accessions, previously resistant to downy mildew, lost their resistance and suffered severe damage from the disease. Hence, it seems obvious that resistant accessions should be periodically retested for susceptibility to downy mildew. Twenty accessions were selected to form a group of tolerant ones. Of these, ‘Yeo leam sam chuk oi’ (k-4545), ‘Crispy Top F1’ (temp. k-3549) and ‘Pchelka F1’ (temp. k-3981) had the highest average yield.

The world’s genebanks hold 7.5 million germplasm accessions of plant genetic resources (PGR). One of the qualitative characteristics of the PGR collections is the species diversity, in particular, the presence of crop wild relatives (CWR), which makes it possible to widen the use of gene pools in the breeding process. The collection of the Vavilov Institute (VIR) is one of the most diverse holdings in the number of plant species. A survey is provided here of the species diversity in VIR’s grain legume collection, and its use in domestic breeding practice is analyzed. Comparison of this diversity with the state of PGR exploitation in the world makes it possible to assess the prospects of more efficient utilization of gene pool potential, especially for species that are unjustifiably cultivated on a too small scale or even neglected as crops in this country. The VIR collection of grain legumes incorporates 196 species from 9 genera of the family Fabaceae. This number includes cultigens and CWR. The cultivars of 21 species of grain legumes listed in the State Register of Breeding Achievements (2018) are adapted to the soil and climate conditions of this country. However, the species diversity of the collection could be used more efficiently in domestic plant breeding and crop production. This concerns both underutilized crops in Russia (broad beans, lima beans and grass pea) and those whose adaptive potential is adjusted only to certain and limited areas of the Russian Federation (Tepary beans and Vigna spp.). It is also necessary to exploit more efficiently species of the wild flora, both for direct utilization as pastures, green manure or phytoremediation crops and for introgressive breeding and domestication (Vicia benghalensis L., V. narbonensis L., Lathyrus sylvestris L., Lupinus hartwegii Lindl., etc.). Incorporation of crop wild relatives into the breeding process is promising for crop improvement in a number of aspects: for example, to increase resistance to diseases, pests, abiotic stressors, etc.

The article is dedicated to the mobilization of plant genetic resources from the territories of Indonesia, Sri Lanka (Ceylon) and Nepal to VIR’s collection by means of collecting explorations, germplasm requests and the exchange of accessions. The first, the longest and the only pre-war expedition to Indonesia and Ceylon was undertaken by Prof. V. V. Markovich; it lasted three years (1926–1928). He explored Java, Singapore and Ceylon, where he collected 772 germplasm samples. In 1957, D. V. Ter-Avanesyan, who worked as an agricultural attaché at the USSR Embassy in India, familiarized himself in every detail with plant resources and agriculture in Nepal. The late 1960s were marked by intensification of plant genetic resources introduction and new opportunities to organize regular collecting missions. In the period from 1960 to 1991, there were five plant exploration trips to Indonesia, Sri Lanka (Ceylon) and Nepal. In 1960, D. V. Ter-Avanesyan visited scientific institutions in Java, got acquainted with the main trends in agriculture, and collected 302 plant samples. In 1974, A. G. Lyakhovkin took part in a specialized collecting mission launched to study and collect wild forms and cultivars of rice and various other crops from Nepal. The team visited 16 experiment stations and farms and collected 1170 accessions. In 1985, an expedition team led by E. F. Molchanov collected and studied wild and cultivated forms of subtropical plants in Sri Lanka. The team visited 5 institutes and experiment stations, 3 botanical gardens, and collected 370 accessions. In 1988, another collecting team led by L. A. Burmistrov, whose task was to study the system of nation-wide projects on crop improvement, traveled over four provinces, visited 11 scientific and academic institutions of Nepal, and collected 766 germplasm samples. The last collecting trip to Indonesia was led by N. G. Musatenko in 1991. The team collected 95 varieties and wild forms. In total, the Institute’s collecting and exploration activities in Indonesia, Sri Lanka (Ceylon) and Nepal added 3496 accessions to its collections. In addition to direct collecting in Indonesia, Sri Lanka (Ceylon) and Nepal, VIR has always been replenishing its holdings by seed requests. During the whole pre-war period, from 1925 through 1941, 256 germplasm accessions were added. All in all, from 1948 through 2018, 104 accessions were introduced from Indonesia, Sri Lanka (Ceylon) and Nepal. The greatest number of accessions received by the Institute represented groat crops (over 1400), followed by wheat and barley (458), and industrial crops (627). In total, during the whole period of its existence, the Institute has mobilized 3843 accessions, representing 377 plant species.