Caucasus Research Articles

Occurrence of Powdery Mildew Caused by Erysiphe corylacearum on Hazelnuts in Israel

Hazelnut (Corylus avellana L) is an emerging crop in Israel, primarily cultivated as a host plant to establish truffle plantations through symbiosis with ectomycorrhizal fungi. A significant damage and yield reduction is caused by the prevalent occurrence of powdery mildew in hazelnut trees (Sezer et al., 2017). Until recently, Phyllactinia guttata was considered the primary pathogen in Western Asia, the Caucasus region, and Europe (Abasova et al. 2018; Arzanlou et al. 2018; Mezzalama et al. 2021). However, in the last years, a new destructive species Erysiphe corylacearum has been identified as the pathogen of powdery mildew on hazelnuts in these regions (Meparishvili et al. 2019; Mezzalama et al. 2021; Kalmár et al. 2022; Zajc et al. 2023). In May 2022, powdery mildew symptoms were observed on hazelnut plants in the Ein-Zivan truffle plantation, gardens of Merom-Golan, and the adjacent garden of the packing house Pri-Beresheet in the northern Golan region of Israel. Symptoms were observed on the abaxial and adaxial leaf surfaces, fruits, and husks. Disease incidence and severity ranged between 30-70% and 5-90%, respectively. Disease severity was significantly greater on the leaves of the offshoots compared to those on the tree canopy. Morphological characterization of leaf samples from ten different trees showed the following characteristics: hyphal appressoria were lobed, solitary, 1–4 μm in diameter; mycelium was amphigenous, hyaline, and septate; conidiophores vertically elevated from the mycelium 50– 80 μm long. Conidia (n= 30) on conidiophores were hyaline, ellipsoid to ovoid, 24 – 34 μm long and 15.5 – 23 μm wide. Chasmothecia in several maturation degrees appeared in October on both sides of the leaves. They were spherical (n= 30) 86 – 125 μm in diameter, with 7 - 14 aseptate straight appendages, 67 - 96 μm long, 4.9 - 7.1 μm wide, dichotomous branched at the end 42 - 56 μm wide. In each chasmothecia, there were 3-5 asci (n=30) with a width of 38 – 43 μm and a length of 48–64 μm of oval-ellipsoid shape. Asci contained 4-8 ascospores (n=30), 18 - 26 μm long and 11 - 15.5 μm wide. A pathogenicity test was conducted to fulfill Koсh’s postulates. Both detached leaves and plants of C. avellana were artificially infected by brushing conidia from infected leaves. Inoculated leaves in Petri dishes on 2% water agar (n= 5), and plants (n= 5) were incubated under 25°C and 12-h photoperiod/day. Untreated leaves and plants served as control. Typical symptoms appeared on the upper surface of the leaves within 7-10 days after inoculation. No symptoms were found on untreated control plants or detached leaves. The fungus isolated from the inoculated leaves was morphologically identical to the original isolates from natural diseased plants. DNA was extracted and the rDNA internal transcribed spacer region of five isolates originated from leaves of the tree canopy and offshoots was amplified using primers ITS1 and ITS4, and sequenced. BLAST analysis of 595 bp fragments (all identical and represented by isolate Cora1, GenBank Accession No. OR752437) showed 99% identity to ITS rDNA sequences of E. corylacearum from Georgia (MK157199) and 100% identity to isolates from Azerbaijan, Turkey and Italy (LC270863, KY082910 and MW045425, respectively) and only 83% similarity to P. guttata (accession number AB080558). To the best of my knowledge this is the first report on E. corylacearum causing powdery mildew in Israel. Future control measures to manage the disease on hazelnuts in truffle plantations in Israel should be considered.

Benefits of ULV Application to Control Locusts in Caucasus and Central Asia

This paper discusses the state-of-the-art of Ultra-Low Volume (ULV) spray application with rotary atomisers in the Caucasus and Central Asian (CCA) region to control locusts. The technology is widely used around the world for locust control and promoted by the UN Food and Agriculture Organisation (FAO) as an effective and efficient control intervention that meets the scale and challenge posed by large area locust outbreaks. The technology utilises precisely controlled spray droplets in the range 50–100um using ready-to-use oil-based ULV formulations to target locusts more efficiently. Volume rates as low as 0.5–1.0 l/ha are utilised which greatly improves productivity of ground and aerial spray applications, timeliness, and reduces cost and waste of pesticide and water. ULV has become more widely adopted in CCA during recent years to control major economic pests such as Moroccan, Italian, and Asian migratory locusts. Its further adoption is hampered by the lack of available ULV formulations in the region and need for investment and training in the technology. ULV technology is highly appropriate for use of biological products to reduce risks to operators and the environment and efforts to increase regional cooperation and the registration of safer pesticides across the region present opportunities for its wider adoption.

Provenance and the U–Pb age constraints on the tuff beds of the Late Jurassic–Early Cretaceous Bazhenovo Formation, West Siberian Basin

AbstractThin tuff beds of the Late Jurassic–Early Cretaceous Bazhenovo Formation are laterally widespread in the central part of the West Siberian Basin (ca 0.5 million km2). However, the source of the tuff beds remains unclear. The stratigraphy, geochemistry and geochronology of the tuff beds were investigated to reveal their magmatic origin and potential source region. Most of the tuff beds are recorded in member 4 and can be correlated through the Bazhenovo sequence. Thin‐section petrography and X‐ray diffraction indicate that the tuffs mostly comprise clay minerals and K‐feldspars. Less common minerals are plagioclase, quartz and pyrite. The geochemical composition of the Bazhenovo tuff beds suggests a parental magma origin of andesite/basalt, which came from volcanic arc‐related settings. Considering the results of geochemical studies along with LA‐ICP‐MS zircon U–Pb dating (141.3 ± 0.3/2.8 Ma), the palaeovolcanoes of the Caucasus region or south‐east Mongolia–North‐East China are one of the potential source regions of the tuffs. The record of these tuffs indicates the intensive volcanic eruption during the Volgian–Ryazanian, accompanied by a very low‐sedimentation rate and preservation in a reducing environment. The tuff beds have broad implications as an isochronous marker horizon and constraints for the numerical age of the Jurassic–Cretaceous boundary in the Boreal Realm.

The first record of the rarely observed rat snake, Elaphe urartica Jablonski et al., 2019 (Squamata, Colubridae) for Iraq

The Urartian rat snake, Elaphe urartica Jablonski, Kukushkin, Avcı, Bunyatova, Ilgaz, Tuniyev & Jandzik, 2019, is a recently described species within the genus Elaphe, found in eastern Anatolia, Caucasian region and the northern Middle East. It stands as one of the rarely observed snake species, with its distribution and other aspects of natural history largely unexplored. This is particularly true for the territories of Iraq and Iran. Therefore, we report on the presence of the species in Iraq, the first documented evidence of the species’ distribution within the country. In conjunction with this record, we provide initial data regarding the species’ habitat and ecology in the region. The distribution record presented here is further supplemented by a new species record from the border regions between Iraq and Iran, encouraging further herpetological exploration within the Zagros Mountains.

Analysing the factor structure of the plurilingual and pluricultural competence scale: dimensionality, reliability, and validity of the adapted Russian version

ABSTRACT This study aimed to adapt the Plurilingual and Pluricultural Competence scale (PPC) to the Russian-speaking population and to assess its psychometric properties. Five hundred and sixty-four undergraduate students from Western, Central, and Caucasian regions of Russia and Kazakhstan participated in the study. Internal consistency, factorial, construct, and criterion validity of the Russian version of the scale (PPCr) were examined. Unidimensional and several competing multidimensional models of the scale's structure were tested against data using confirmatory factor analysis. The final model included four first-order factors (plurilingual conversation, plurilingual cognition, intercultural tolerance, and intercultural skills) and two second-order factors (plurilingual competence and intercultural competence). The PPCr scale demonstrated good internal consistency and criterion validity. The PPCr total and plurilingual subscales scores significantly correlated with language repertoire and overall language proficiency self-assessments. Regional differences in the total PPCr score, plurilingual conversation, and intercultural tolerance scores were documented. These findings were discussed in the context of research and assessment of PPC in different socio-cultural environments. We recommended not contrasting unidimensional and multidimensional models of PPC but considering them two poles on the continuum. It suggests transitioning from a multidimensional to a unidimensional model when an individual acquires more plurilingual and pluricultural experience.

Evaluation of potato varieties by productivity and adaptability in the conditions of the North Caucasus region

Evaluation of potato varieties by productivity and adaptability in the conditions of the North Caucasus region

Resistance of potato hybrids to viral and fungal diseases in the conditions of the North Caucasus region

Resistance of potato hybrids to viral and fungal diseases in the conditions of the North Caucasus region

Impact of Türkiye’s Dam Construction on the Water Resources of the Transboundary Aras River Basin in Iran

Abstract The Aras River Basin, a significant transboundary river basin in the Caucasus region, is shared among four riparian countries, including Türkiye, Armenia, Iran, and Azerbaijan. Although positive measures have been taken to enhance water cooperation in this river basin, the Eastern Anatolia Project (DAP) and the hydraulic mission of Türkiye remain the primary factors that could potentially reverse the cooperative atmosphere of the basin and lead to conflict. In recent decades, Türkiye has utilised transboundary water resources to bolster its economic power, advance political strategies, and establish hydro-hegemony. Despite the significant Mega-Project and hydraulic mission of the upstream in the Aras River Basin, they have not received adequate attention in hydro politics studies. This study employs secondary sources to investigate Türkiye’s actions in the region. It discusses the implications of Türkiye’s projects on downstream riparian states in general and Iran’s water resources, including dam construction.

An Analytical Review of the Recent Crustal Uplifts, Tectonics, and Seismicity of the Caucasus Region

This paper analyzes and reviews the rapid uplifts of the Earth’s crust in the Caucasus that occurred over the last century. The uplifts were registered by precise repeated state leveling and reflected on officially published maps of vertical movements of the Earth’s crust. This study summarizes information on the region’s vertical movements over more than a century. The present study describes the technology for creating maps of recent vertical movements of the Earth’s crust using precision leveling data. This paper summarizes cases of recording uplifts of the Earth’s surface in other regions of the world in connection with seismic activity. The authors carried out intercomparison of vertical movements with tectonics, seismicity, and geophysical fields, which discovered their apparent mutual correspondence. This indicates the deep tectonic nature of the observed uplifts of the Earth’s crust. Spatial and temporal agreement with the distribution of strong earthquakes showed a natural relationship. It has been shown that strong earthquakes are confined to the boundaries of zones of rapid uplift. They occur predominantly in areas of transition between uplifts and subsidence. The results obtained demonstrate the role of the study and observations of vertical movements of the Caucasus in assessing periods and areas of increased seismic hazard.

A renewed glance at the Palearctic golden eagle: Genetic variation in space and time.

Anthropogenic pressures on nature have been causing population declines for centuries. Intensified persecution of apex predators, like the golden eagle, resulted in population bottlenecks during the 19th and 20th centuries. To study population genetics and demographic history of the golden eagle throughout its distribution, we collected museum samples from previously underrepresented regions, such as Russia and Central Asia. We used 12 microsatellite loci and a fragment of the mitochondrial DNA control region to re-evaluate phylogeography of Eurasian golden eagles and study the impacts of the population bottleneck. Our results revealed a north-south genetic gradient, expressed by the difference between Mediterranean and Holarctic lineages, as well as genetically distinct Northern Europe and Central Asia and Caucasus regions. Furthermore, Northern Europe exhibited the lowest, whereas Central Asia and Caucasus had the highest genetic diversity. Although golden eagles maintained relatively high genetic diversity, we detected genetic signatures of the recent bottleneck, including reduced genetic diversity and a decline in the effective female population size around the year 1975. Our study improves the knowledge of the genetic composition of Eurasian golden eagles and highlights the importance of understanding their historical population dynamics in the face of ongoing and future conservation efforts.

The image of the Chechen War on the pages of the American daily newspaper The New York Times: headline review

The subject of the research in the article is the image of the First and Second Chechen Wars, created by journalists of The New York Times newspaper in the 1990s and reflecting the views of the American democratic public. The subject of the study is the headlines of articles related to this topic in the American daily newspaper The New York Times. At the end of the 20th century, the periodical press continued to play a significant role in public life, including shaping the news agenda and creating the image of certain events. Often, journalists sought to impose their vision of Russian politics on the reader. Reputable publications, avoiding the techniques of the "yellow press", used more subtle and unobvious manipulative forms. Such manipulations include the newspaper's choice of lexical units with a certain connotation and the frequency of their use. In this study, the author attempts to explicate the hidden information that is embedded in the headlines of The New York Times. To analyze the information identified by the author in the headlines of The New York Times newspaper, the article used methods such as historical, comparative and quantitative content analysis. The novelty of the study lies in the fact that the headlines of The New York Times newspaper of this period were first considered as a source of analysis of the transforming view of the American democratic press on the events of the First and Second Chechen Wars. According to the results of the study, the following conclusions were drawn: the image of the Chechen conflict of the 1990s in the American press has undergone significant changes. If the First Chechen War in The New York Times appears as a legitimate struggle of the Russian authorities against the separatist movement in Chechnya, albeit with a number of critical remarks, then the image of the Second Chechen War is radically different from the previous campaign. The newspaper presents the events of the Second Chechen Campaign as a new colonial war, while the emphasis was shifted towards criticizing the Russian leadership for violating human rights and freedoms in the Chechen Republic, as well as a direct impact on destabilization in the North Caucasus region.

Biomorphological features and antioxidant activity of mint species of non-hybrid origin growing in the North Caucasus region

Introduction. Modern researchers note the role of antioxidants in the correction of fat and carbohydrate metabolism, so the search for new raw materials for obtaining substances with antioxidant activity is relevant. Polyphenolic compounds are considered the most powerful natural antioxidants. Our attention was drawn to non-hybrid mint species growing in the North Caucasus region. Objective. Study of biomorphological features and economically valuable characteristics of the species Mentha L. (Lamiaceae), their phytochemical characteristics based on the content of essential oil and some phenolic compounds, determination of antioxidant activity to substantiate the prospects for use in medicine and pharmacy. Material and methods. The studies were carried out according to the methods of the State Pharmacopoeia (SP) XIV and XV editions. Samples of raw mint (M. arvensis L.), watermint (M. aquatica L.), longleaf mint (M. longifolia (L.) Huds.), flea mint (M. pulegium L.), m spicata (M. spicata L.), harvested in forest-steppe and steppe zones, as well as on mountain slopes, damp places, sometimes in wastelands, in North Ossetia – Alania, Karachay-Cherkessia, Kabardino-Balkaria and the Stavropol Territory in their natural places of growth (end of July–August 2021–2023). Objects were dried using the air-shadow method. Antioxidant activity was determined by amperometric and titrimetric methods. Results. Non-hybrid mint species growing in the North Caucasus contain essential oils, hydroxycinnamic and triterpene acids, flavonoids and polyphenolic compounds. The established antioxidant properties of hydroalcoholic extracts of mint species, in addition to the traditionally known choleretic and antispasmodic effects, can be considered significant for reducing body weight. Conclusion. The content of essential oil and polyphenolic compounds in various types of mint, as well as the established antioxidant properties of aqueous-alcoholic extracts, in addition to the traditionally known choleretic and antispasmodic effects, can be considered significant for weight loss.

KIRIM SAVAŞI'NDA KUZEY KAFKASYA

The Crimean War is one of the important turning points in Ottoman-Russian relations. While the Ottoman Empire tried to maintain its declining influence in the Black Sea with the support of its European allies, Russia tried to increase its influence in both the Balkans and the North Caucasus. Against this policy of Russia, the resistance groups in the North Caucasus tried to gain the support of the Ottoman Empire and its allies, while trying to create unity among themselves. The movements in the North Caucasus, which were far from forming any unity and providing organized resistance, ended after the war when Russia launched a total occupation and colonization activity in the Caucasus region. The war and resistance in the region gave way to one of the greatest tragedies in history, in which hundreds of thousands of Circassians were exiled and subjected to massacres. In this study, the situation in the North Caucasus during and after the Crimean War will be evaluated.

The Main Stages of the Armenian-Azerbaijani Conflict and the Consequences of the Conflict

The South Caucasus region has always been an important player in regional geopolitics, closely connected with the national interests and security of Russia, Iran, and Turkiye. Its significance increased significantly after the Soviet Union's collapse. The region is a strategically vital transport hub, where communication and trade routes from East to West (the ancient Silk Road) and from South to North intersect. However, ongoing conflicts between Georgia, Abkhazia, and South Ossetia, as well as between Azerbaijan and Armenia, have hindered the region's economic development. These conflicts have partially blocked the region, which has crucially impacted its political development. The most dangerous conflict is between Armenia and Azerbaijan over the status of Nagorno-Karabakh. In 2020, Azerbaijan regained control of seven regions around Karabakh, which were occupied by Armenians during the first Armenian-Azerbaijani war in the early 1990s. In 2023, during a one-day special operation, Azerbaijan established full control over the territory of the former Nagorno-Karabakh Autonomous Region. The Azerbaijani army's victorious military operations have changed the balance of forces, opening up new opportunities for strengthening peace and developing economic, political, and cultural cooperation between the countries of the region. This paper examines how the Armenian-Azerbaijani confrontation impacted on the geopolitical situation in the South Caucasian region. The official and historical documentation as well as diplomatic reports and media outlets analyzed for these purposes. The comparative-descriptive method was applied to analyze the sources.

The first record of Hemineura wittmeri Badonnel, 1981 (Psocodea, Psocomorpha, Elipsocidae) from the Caucasus

The second psocid species of the genus Hemineura Tetens, 1891, namely H. wittmeri Badonnel, 1981, is recorded from the Caucasus region for the first time based on several female and male specimens collected in the Shida Kartli region of Georgia. Collecting data are given along with diagnostic illustrations of the preserved specimens.

Biogeographic history of Pterocarya (Juglandaceae) inferred from phylogenomic and fossil data

AbstractPterocarya (Juglandaceae) is disjunctly distributed in East Asia and the Caucasus region today, but its fossils are widely distributed in the Northern Hemisphere. We first inferred phylogeny with time estimation of Pterocarya under node‐dating (ND) based on plastomes of all eight extant species and tip‐dating (TD) based on plastomes and 69 morphological characters of 19 extant and extinct species, respectively. We compared the biogeographical reconstructions on the timetrees from ND and TD, respectively, and then compiled 83 fossil records and 599 current occurrences for predicting the potential distributions for the past and the future. The most recent comment ancestor of Pterocarya is inferred in East Asia at 40.46 Ma (95% highest posterior density [HPD]: 28.04–54.86) under TD and 26.81 Ma (95% HPD: 23.03–33.12) under ND. The current distribution was attributed to one dispersal and one vicariant event without fossils, but as many as six dispersal, six vicariant, and 11 local extinction events when considering fossils. Pterocarya migrated between East Asia and North America via the Bering Land Bridge during the early Oligocene and the early Miocene periods. With the closure of Turgai Strait, Pterocarya dispersed between East Asia and Europe through the Miocene. The potential distribution analyses indicated that Pterocarya preferred warm temperate regions across the Northern Hemisphere since the Oligocene, but the drastic temperature decline caused its extinction in high latitudes. Except for Pterocarya fraxinifolia and Pterocarya stenoptera, suitable habitats for this genus are predicted to contract by 2070 due to climate change.

Autonomization in the management of the region of the Russian Empire on the example of the Caucasian territories in the second half of the XIX century

The article, primarily on the basis of legislation and archival materials, consistently examines the conditions, ideas, directions and means of autonomy in the management of the Caucasus region. Maintaining the stability of the unified political and legal space of the imperial state required the authorities to carry out systematic measures taking into account the socio-political and legal traditions of the local multi-ethnic population. The author analyzes various kinds of legislative acts regulating the features of the official status of the governor in the Caucasian territories of the Russian Empire. The military-people’s administration, the predominant role in the local administrative system of the Ministry of War led to the subordination of the administration of the region to a predominant extent directly to the emperor.

Process optimization for green synthesis of silver nanoparticles using Rubus discolor leaves extract and its biological activities against multi-drug resistant bacteria and cancer cells

Multi-drug resistant (MDR) bacteria are considered a serious public health threat. Also, increasing rate of resistance to anticancer drugs, as well as their toxicity, is another point of concern. Therefore, the new antibacterial and anticancer agents are always needed. The synthesizing silver nanoparticles (AgNPs) using medicinal plants, is an effective approach for developing novel antibacterial and anticancer agents. Rubus discolor, a native species of the Caucasus region, produces leaves that are typically discarded as a by-product of raspberry production. The present study has focused on optimizing the green synthesis of AgNPs using R. discolor leaves extract through response surface methodology. The optimal values for AgNPs synthesis were an AgNO3 concentration of 7.11 mM, a time of 17.83 h, a temperature of 56.51 °C, and an extract percentage of 29.22. The production of AgNPs was confirmed using UV–visible spectroscopy (λmax at 456.01 nm). TEM analysis revealed well-dispersed AgNPs (an average size of 37 nm). The XRD analysis confirmed the crystalline structure. The EDX detected a strong peak at 3 keV corresponded to Ag. The zeta potential value (− 44.2 mV) indicated the stability of nanoparticles. FT-IR spectra showed the presence of various functional groups from plant compounds, which play an important role in the capping and bio-reduction processes. The AgNPs revealed impressive antibacterial activities against MDR Escherichia coli and Pseudomonas aeruginosa (MIC ranging from 0.93 to 3.75 mg ml−1). The phytochemical analysis indicated the presence of phenolics, tannins, and flavonoids on the surface of AgNPs. They also showed significant cytotoxic effects on A431, MCF-7, and HepG2 cells (IC50 values ranging from 11 to 49.1 µg ml−l).

Western Caucasus regional hydroclimate controlled by cold-season temperature variability since the Last Glacial Maximum

The Caucasus region is key for understanding early human dispersal and evolution in Eurasia, and characterizing the environmental contrast between Last Glacial Maximum and Holocene is crucial for investigating human adaptation strategies to large climatic shifts. However, a paucity of high-resolution paleoclimate records leave this context largely unknown for early human populations in the Caucasus region. Based on our model-proxy comparison of high- and low-resolution records of 24 stalagmites from three caves, we find spatially distinct changes in vegetation and seasonality of precipitation, especially under glacial conditions. Supported by modern oxygen-isotope data and climate modeling, we identify a supraregional cold-season temperature control for oxygen isotopes in Black Sea speleothems, which previously had been interpreted as a local moisture-source signal. Carbon-isotope and trace-element data further suggest disproportionate changes in vegetation cover and soil dynamics at high altitudes, which would have resulted in a reduction but not a disappearance of human refugia during the Last Glacial Maximum, relative to the current interglacial. Our findings imply that abrupt climatic pressures from harsh conditions were overcome by adaptive strategies in the past.

High-Precision Cyclic Correlation as a Basis for Detailed Paleoclimatic Reconstructions for Crimean–Caucasian Region in the Jurassic

High-Precision Cyclic Correlation as a Basis for Detailed Paleoclimatic Reconstructions for Crimean–Caucasian Region in the Jurassic