Favorable Environmental Conditions Research Articles

Mathematical Modeling of Population Dynamics of Trogoderma granarium (Coleoptera: Dermistidae).

Khapra beetle, Trogoderma granarium Everts, is one of the economically important quarantine pests that mainly feeds on food grain and proteinaceous materials. Its total development time lasts approximately 40-45 d under favorable environmental conditions. Extreme temperatures, high relative humidity (RH), high larval densities, or low food quality can induce a larval diapause, where the insect can survive for up to a few years, occasionally feeding and molting. Ecological modeling is a helpful tool to study the population dynamics of biological systems. Physi-Biological age method is based on temperature-driven development rate, and factors such as RH and food quality were considered as multipliers. The objective of this study was to develop mathematical models to calculate the survival and development of adults, eggs, larvae, pupae, and oviposition and diapause under different environmental conditions such as temperature, RH, and food quality. Algorithms were developed to simulate the population dynamics for each day and coded in C++. The developed models were validated against the literature data and evaluated using linear regression, R2, and MSE. Population dynamics were simulated under Canadian grain storage conditions, and the developed models predicted that the diapausing larvae survived the extremely cold conditions found in Canadian grain. In contrast, other stages did not survive. The surviving larvae developed to pupae and adults, and females began laying eggs once the temperature became warmer in the grain bins.

WHEAT STRIPE RUST AND INTEGRATION OF SUSTAINABLE CONTROL STRATEGIES IN CHINA

<List> <ListItem><ItemContent> • Stripe rust caused substantial yield losses in China. </ItemContent></ListItem> <ListItem><ItemContent> • <i>P. striiformis</i> is highly variable and the change from avirulence to virulence. </ItemContent></ListItem> <ListItem><ItemContent> • Different comprehensive control strategies were adopted in different epidemic region. </ItemContent></ListItem></List> Stripe (yellow) rust caused by <i>Puccinia striiformis</i> f. sp. <i>tritici</i> occurs in almost all wheat-producing regions of the world. Severe countrywide epidemics in China have caused substantial yield losses. Growing resistant cultivars is the best strategy to control this disease but the pathogen can overcome resistance in wheat cultivars. The high variation in the virulence of the pathogen combined with the large areas of susceptible wheat cultivars enables the pathogen population to increase rapidly and disperse over long distances under favorable environmental conditions, resulting in severe pandemics within cropping seasons. Current stripe rust control measures are based on many years of research including the underlying epidemiology regarding year-to-year survival of the pathogen, pathways of pathogen dispersal within seasons and years, the role of <i>P. striiformis</i> sexual hybridization, the use of resistance sources in breeding programs, and year-round surveillance of national wheat crops that are present in different parts of the country throughout the year. All these strategies depend on accurate prediction of epidemics, more precise use of fungicides to meet national requirements and better deployment of resistance genes. New ideas with potential application in sustainable protection of stripe rust include negative regulatory gene editing, resistance gene overexpression and biological control based on microbiomes.

数値シミュレーションで得られた上陸前の台風Faxai (1915)の強度・構造変化

A numerical simulation of Typhoon Faxai (1915), which made landfall with a central pressure of 960 hPa in the Kanto region of Japan, was conducted using a nonhydrostatic numerical model with a 1-km grid spacing. Faxai sustained a symmetric structure until the landfall and caused severe damage due to strong winds. The simulation successfully simulated the realistic track and intensity of Faxai for 48 h around landfall. The simulated intensity was strong until the time of landfall, and the spatial size of the vortex was small. The structure of the simulated Faxai, identified as having an axisymmetric flow field and eyewall, was similar to that of a welldeveloped tropical cyclone (TC) in the tropics. Around the TC center, the surface latent heat flux was over 300 W m−2 until landfall, and the vertical wind shear was less than 9 m s−1 between the 1.5- and 12.0-km altitudes, which is relatively weak at midlatitudes. The maximum potential intensity (MPI) was calculated using environmental parameters around the simulated TC. The simulated and best track TC intensities exceeded the MPI for approximately 12 h before landfall, that is, the TC was in a superintense state. The superintensity was mainly caused by the presence of supergradient wind, which, in turn, resulted from the strong intensity and axisymmetric structure of the typhoon. The simulated TC satisfies the assumptions for the formulation of the MPI during the quasi-steady state, except for the gradient wind balance, implying that the structure of a TC is similar to that of a developed TC in the tropics. The present analyses suggest that the strong intensity of Faxai results from favorable environmental conditions and vortex structure.

Ekonomski značajne vrste grinja (Acari: Tetranychidae; Eriophyidae) na jabuci

Under favorable environmental conditions, mites can represent a significant problem in apple production. Several types of mites are found on apples, only a few are of economic importance: Panonychus ulmi, Tetranychus urticae, T. turkestani and Aculus schlechtendali. All the mentioned species have a high reproductive potential, which in warm and dry conditions leads to a rapid growth of populations. The period of activity and feeding of mites begins in spring and lasts until autumn, and the most pronounced symptoms are noticeable during the summer months. Nutrition and leaf tissue damages cause chlorosis and/or necrosis, photosynthetic disorders, increased transpiration, defoliation, fruits remain small, lose quality and decline, so yield losses can be extremely large.

Retarded Swarming Motility in Bacillus Subtilis NRS-762 and Pseudomonas Aeruginosa PRD-10

Coping with nutritional stress is essential for cell survival, of which many strategies at the cellular level lend support for ensuring the survival of the population at a particular habitat. One postulated mechanism is swarming motility in bacterial cells, where, upon depletion of nutrients at a locale, cells would coordinate their movement, synthesize more flagella, and secrete lubricants for moving rapidly across surfaces in search for food. Known to engage in swarming motility, Bacillus subtilis and Pseudomonas aeruginosa are two common bacterial species with versatile metabolism that use the motility mode to colonize new habitats with more favourable environmental and nutritional conditions. However, experimental observations of bacteria growth on a variety of agar media revealed that B. subtilis NRS-762 (ATCC 8473) and P. aeruginosa PRD-10 (ATCC 15442) exhibited retarded swarming motility upon entry into stationary phase on solid media. Specifically, B. subtilis NRS-762 colonies exhibited round, wrinkled morphologies compared to complex filamented swarming patterns common in strains able to engage in swarming motility. On the other hand, P. aeruginosa PRD-10 colonies were round, mucoid, and expanded outwards from the colony centre without extending filaments from the centre; thereby, indicating retarded swarming motility. Thus, impaired cellular machinery for swarming motility or mutated and deleted genes likely account for observed retarded swarming motility in B. subtilis NRS-762 and P. aeruginosa PRD-10. More importantly, observations of small filaments extending radially from an expanded colony of P. aeruginosa PRD-10 grown on minimal salts medium supplemented with yeast extract highlighted possible loss of function of effector molecules that transmit cellular decision at swarming motility into movement, while sensory mechanisms feeding into the motility mechanism remained intact. More broadly, observations of impaired swarming motility in B. subtilis NRS-762 and P. aeruginosa PRD10 in two species otherwise endowed with the motility mode highlighted the presence of additional triggers for swarming motility are likely present, and the motility mode may have been evolutionary selected for other functions in addition to foraging for food in times of nutritional stress Graphical Abstract.

Prerequisites for taking into account the influence of air exchange in the design of residential districts in the regulatory documentation

Many cities face environmental problems, which are currently receiving a lot of attention. The layout of the city' micro-district corresponding to the regulations can provide the most favorable environmental conditions due to air exchange. The building of the city has been developing for centuries, microdistricts have a layout that was regulated by the law, valid at the times of their construction. The object of research is the processes of air exchange in city districts – on the example of Krasnoyarsk. The method of analysis of scientific sources and standards was used for the study, which allowed determining the chronology of changes in factors affecting air exchange and building blocks. The study includes the solution of the following tasks: analysis of the building regulations affecting air exchange in the neighborhood; to determine the principles of planning a residential neighborhood and establish their compliance with the standards on the example of the city of Krasnoyarsk; to consider the prerequisites for the implementation of an environmental aspect in building codes. For the sake of clarity of the data obtained on the problems of air exchange and the principles of development of microdistricts, the history of the planning structure of the development of Krasnoyarsk is investigated. As a result of the study, a general characteristic of the development of regulatory requirements for the development of microdistricts has been identified and presented. The relevance of the topic is determined by the presence of a problem with the accumulation of harmful substances in residential neighborhoods in Krasnoyarsk. In the current planning methods of development in some residential areas of Krasnoyarsk, this problem cannot be solved due to the increase in height and density of buildings while maintaining the same values of distances between buildings, since the regulatory requirements of insolation do not ensure effective ventilation of the district. According to the results of the study, it was concluded that not all previous standards included effective regulations to ensure the necessary air exchange, or they are completely absent. In these standards, factors affecting effective air exchange (height of buildings, distances between buildings and the angle of the buildings) were determined by other requirements, such as sanitary and fire safety standards, insolation requirements.

Риски возникновения опасных инфекционных болезней животных на юго-востоке Российской Федерации

The article analyzes the epizootic situation in the Republic of Buryatia, considers veterinary problems associated with the special geographical status of the region, which is located in the southeast of the Russian Federation. The republic borders on Mongolia, the Trans-Baikal Territory, which has common borders with China. The intensification of international trade, tourism, interstate movement of various goods, animals, the deterioration of the epizootic situation in the world, the lack of anti-epizootic measures in the new economic conditions increase the risk of outbreaks of dangerous diseases. The occurrence of anthrax was caused by insufficient accounting and lack of passportization of old burial sites, cattle burial grounds, grazing of unvaccinated cattle on unfavorable pastures, activation of soil anthrax outbreaks. Taking into account these and other risks of possible outbreaks of anthrax, epizootic well-being is maintained in the republic through preventive vaccination of susceptible animals. The territorial proximity of adjacent territories epizootically unfavorable for rabies (Mongolia, the Trans-Baikal Territory), favorable environmental conditions for foxes (steppes and mountain slopes, the valley of the Selenga, Dzhida and their tributaries), the presence of a large number of susceptible animals, were the main components of the development of the epizootic process of rabies among foxes, whose attacks have caused cases of rabies among farm animals, in particular cattle. Infectious nodular dermatitis of cattle had serious consequences for the agricultural sector of the Trans-Baikal Territory, the Republic of Buryatia, where livestock is mainly concentrated in personal subsidiary plots and is of great help in the economic and social life of the villagers. In this regard, it is necessary to expand monitoring of the disease in the Far Eastern and Siberian Federal Districts and adjacent regions. The southeastern territories of the Russian Federation are defined as areas of risk for FMD. Carrying out specific prevention of foot-and-mouth disease makes it possible to contain the factors of the epizootic risk of foot-and-mouth disease in transboundary territories and in general in the Republic of Buryatia.

Characteristics of the adaptive properties of winter soft wheat varieties in the conditions of the Middle Volga region

The paper deals with the obtained results of examining the adaptive properties of winter wheat varieties cultivated in the seventh (Middle Volga) region of the Russian Federation. The following varieties were taken as the object of the current research: Bezenchukskaya 380, Nemchinovskaya 57, Scepter, Moskovskaya 56, Fotinya, Klaudia 2. This research was carried out with the aim to improve the efficiency of grain production. The chosen varieties had been studying at six levels of mineral nutrition over three years. The indicators obtained by years of research (without fertilization), characterizing the attitude of genotypes to the conditions prevailing during the growing season of crops, were considered as the influence of unregulated environmental factors. The indicators obtained during the application of fertilizers were assessed as controlled environmental factors. The adaptive properties of winter wheat varieties were assessed by indicators characterizing potential adaptability or potential productivity, resistance to stress and the intensity of reaction to favorable environmental conditions. Taking into consideration the adaptive properties of the winter wheat varieties, it was found that they are mainly potentially productive forms, but varieties differ significantly in stress resistance and reaction to favorable environmental conditions. As a result of a comprehensive assessment, conclusions were made about the advisability of using a particular variety in technologies with different levels of cultivation intensity. Firstly, the varieties such as Bezenchukskaya 380, Fotinya and Claudia 2 should be used in technologies of moderate intensity. Secondly, it would be more efficient to cultivate the varieties Nemchinovskaya 57 and Scepter using intensive technologies. Thirdly, the variety Moskovskaya 56 could be cultivated with applying both moderate and high-intensity technologies.

Temporal genetic structure of a stock of Prochilodus lineatus (Characiformes: Prochilodontidae) in the Mogi-Guaçu River ecosystem, São Paulo, Brazil

Abstract Prochilodus lineatus is a species of migratory fish widely distributed in the Paraná River basin, found mainly in the Grande, Pardo and Mogi-Guaçu rivers located in a well-developed region of the state of São Paulo. This study analyzes the genetic diversity and population structure in shoals of P. lineatus based on temporal analysis of specimens sampled over the years 2003, 2005, 2006, 2009, 2010, and 2015 in the Mogi-Guaçu River, São Paulo, at the region of Cachoeira de Emas. Genetic analysis performed using the D-Loop and seven microsatellite marker revealed significant genetic variability in all sampled groups. Moderate levels of structuring between groups were identified with the microsatellite markers (Fst = 0.14), while the mitochondrial marker did not reveal patterns of genetic structuring (Fst = 0.01). The genetic variability fluctuated over time, characterizing patterns of structuring among the analyzed samples. The occurrence of environmental alterations resulting in increased mortality rates, as well as changes in the water level in the ecosystem, among other factors, could determine changes in the reproductive behavior of species. The lack of favorable environmental conditions for reproduction in the basin, as reflected by tests of population bottlenecks, could have resulted in the differentiation of populations of P. lineatus over time.

Ecoepidemiology of dengue in Brazil: from the virus to the environment

Dengue is an infectious disease caused by the dengue virus. In Brazil, the main vector is the mosquito Aedes aegypti (L.); however, Aedes albopictus (Skuse) can also transmit this pathogen. According to the WHO, more than 125 countries are endemic for dengue, and an estimated 50-100 million infections occur annually. In Brazil, the Northeast region is one with high incidence rates and records of successive epidemics. Dengue has been circulating in Brazil for over 30 years, due to the fact that there are areas that offer favorable environmental conditions, as well as municipalities with low socioeconomic conditions and frequent water crises. In addition, Brazil is a tourist hub with an intense flow of visitors, keeping the doors open for the entry and circulation of vector-borne diseases. The role of epidemiology is to analyze the distribution of diseases and their determinants in space and time and to unveil the social inequalities that influence the health-disease process. Thus, a review study that describes the occurrence of Dengue may provide a perspective of future areas of greater risk for dengue epidemics.

Efficacy of Indigenous Knowledge and Selected Modified Storage Structures to Insect Pests of Maize during Home Storage: A Review

Maize (Zea mays L) is an important food crop in Ethiopia and is produced in a number of agro ecologies in the region. Despite the favorable environmental conditions for its production, maize is infected by several insect pests before and after harvest, due to poor pre- and post-harvest practices/handling. Farmers store the produce for two reasons; for home consumption and marketing. They may not accept improvements which incur costs when storing primarily for home consumption. Thus, this review will assess the use of indigenous knowledge and modified storage structures to store maize by controlling postharvest insect pests. The use of indigenous knowledge has been seen by many as an alternative way of promoting development in poor rural communities in many parts of the world. Most developing countries are in the tropics, often in areas of high rainfall and humidity. These conditions are ideal for the development of micro-organisms and insects which cause high levels of deterioration of crops in store. Food losses during storage are the result of biological, chemical or physical damage. In earlier times various indigenous items and methods were used for storage of household items including food items, clothing and bedding etc. The shelf life or storage span of items was increased using readily available and low cost items like mineral substances (ash, sand, table salt, camphor, and inert dust) and other different plant materials and they are the common methods adopted by majority of the rural farmers for storing the grains although majority of them are not aware of the reasons or qualities of these materials and are using them as age old wisdom. Modified storage structures such as hermetic storage, bamboo mat with mud plastering, jute bag with inner plastic lining, metal bins and others are another technique adopted by farmers for maize storage. So it can be concluded that many of the indigenous practices find credibility even in today’s period. Moreover, their user-friendly approach, local availability associated with scientific reasoning provides enjoyment and satisfaction to the users. It must therefore be encouraged to use only those eco-friendly practices that are known to be both safe and effective. These practices must be modified to make them more efficient for further transfer to the end users in the future.

Urban arbovirosis in the state of São Paulo, Brazil: A retrospective study.

Dengue represents one of the most important arboviruses in public health, and its etiological agent is transmitted by the bite of dipterans of the genus Aedes. Every year this disease affects a large part of the population of the state of São Paulo in Brazil, particularly due to the availability of favorable environmental conditions for the growth and development of the vector mosquito. This study aimed to verify the distribution of urban arboviruses in the municipalities of the state of São Paulo and the successful experiences of municipal governments to reduce cases, to highlight strategies that have successfully culminated, and which can serve as a basis for prevention strategies. Information taken from government databases of the Ministry of Health and demographic data were used, where the incidence rate of 14 selected municipalities in the region of Vale do Paraíba between 2015 and 2019 was determined, and an attempt was made to evidence the strategies used to reduce cases. High incidence rates were observed in 2015 and 2019 concerning the other years of the historical series, due to environmental factors and the variation in the circulating strain. The observed data allowed us to infer that the prevention strategies recommended by the evaluated municipalities had a positive effect in the years 2016 to 2018, but unforeseen a priori factors culminated in epidemics, revealing the importance of implementing epidemiological studies using advanced mapping tools, as a way of to minimize the risk of future epidemics.

Epikarstik Kuşağın Denetiminde Gelişmiş Mağara Örneği Olarak: İkiz İncirli Çengirek (Marmaris - Muğla)

During the cave research in Bozburun Peninsula, it was understood that İkiz İncirli Çengirek (cave), one of the many caves discovered, was formed by speleogenetic processes at the epikarstic zone. The formation of many caves in the Bozburun Peninsula region is due to the numerous weak tectonic lineations, suitable climatic conditions, lithology needed for cave formation, and exposure to long-time denudation. Speleogenetic researches carried out in Turkey ignored the role of the epikarstic zone. İkiz İncirli Çengirek is an excellent example for evaluating the impacts of processes in the epikarstic zone on the speleogenesis of the cave. Tectonic weaknesses occurred as a result of tectonic movements during the İkiz İncirli Çengirek formed through tectonic weaknesses that happened as a result of tectonic movements during the Plio– Pleistocene, provided the necessary conditions for the formation of İkiz İncirli Çengirek Cave at that location. Dripping and water-film action in the epikarstic zone under the control of fluviokarstic processes shaped and deepened the morphological structure of the cave. As a result of favorable environmental conditions, the cave is home to many species of Lyciasalamandra flavimembris, cave grasshoppers belonging to the Dolichopoda sp. genus, and other organisms, such as bats, scorpions, and spiders whose species are yet to be identified.

Influence of light indicators on the development of Clarias gariepinus during early ontogenesis

High-quality and fast fish farming is very relevant and in demand nowadays. The african clary catfish is one of the representatives of aquatic organisms, which makes it possible to study complete embryogenesis in a short time in order to understand what favorable environmental conditions are necessary to obtain a larger volume of marketable fish. The aim of our study is to study the early stage of ontogenesis of Clarias gariepinus under the influence of changes in the degree of illumination of the environment. The material for the study was eggs obtained from females at the age of 2 years. The incubation was carried out on special mesh trays located on the surface of the pools. A total of 91000 eggs were laid for incubation. The eggs were fertilized by artificial insemination. The fertilized eggs were kept at an optimum temperature of 28,5°C. The first group was incubated in the dark, and the second under fluorescent lamps. Every 5-15 minutes, eggs were placed in a Petri dish and the material was counted and photographed using a digital camera.The results of our research showed that 20 minutes after fertilization, the onset of blastodisc formation was recorded in both groups. After 35 minutes, cell cleavage begins. The duration of this period is considered from the moment of cleavage until the complete overgrowth of the embryonic disc with cells. After 80 minutes, further division of the embryonic cell occurs with the formation of a spherical structure - morula, as well as the overgrowth of the yolk with the embryonic layer. Later 15 hours, after fertilization, we found that the development of the embryo occurs evenly, with positive dynamics, regardless of illumination.An analysis of the results obtained allows us to conclude that changes in light parameters do not have a negative effect on the rate of development of the Clarias gariepinus eggs.

Numerical simulation of the microphysics and liquid chemical processes occur in fog using size resolving bin scheme

This research aims to understand the role of the initial hygroscopicity of aerosol particles, scavenging mechanisms and of aqueous chemistry in the evolution of the aerosol size distribution. A box model with a size resolving moving bin scheme is used to simulate the fog events over Budapest (Hungary) and Delhi (India). The results from the study are as follows: (i) Aerosol particles can be washed out from the atmosphere more efficiently by Brownian and phoretic scavenging than by activation processes. The efficiency of scavenging mechanisms depends on the size distribution of the dry aerosol particles and the size dependence of the hygroscopicity of the aerosol particles. The efficiency of the phoretic scavenging is also impacted by the duration of the dissipation phase of the fog. (ii) The liquid-phase chemistry, which occurs inside the droplets due to their long residence times in the atmosphere, significantly impacts the size distribution of the regenerated particles. (iii) The liquid-phase chemistry also impacts the hygroscopicity of the regenerated aerosol particles. The enhancement of the concentrations of NH4+, NO3− and S(VI) ions inside the droplets result in a substantial increase of the hygroscopicity of the water-soluble particles. This higher hygroscopicity may impact the fog dissipation by increasing the solution effect and helps to uphold successive fog events under favorable environmental condition.

Spatial population genetic structure and colony dynamics in Damaraland mole-rats (Fukomys damarensis) from the southern Kalahari

BackgroundNon-random associations within and among groups of social animals can provide valuable insight into the function of group living and the evolution of social behaviour. Damaraland mole-rats (Fukomys damarensis) demonstrate extremely high levels of reproductive skew, and dispersal is considered to be male-biased in onset and frequency, although asymmetry in dispersal distance is yet to be investigated. Dispersal may be positively correlated with increasing favourable environmental conditions, such as rainfall, however, the effects of ecological constraints on dispersal and colony fission–fusion dynamics have not previously been demonstrated on a spatial scale. Here we provide the first spatial population genetic study for this species. We investigated genetic structure in a population of Damaraland mole-rats from the southern Kalahari in South Africa over 3 years, combining observational dispersal data from mark-recapture with population genetic data to evaluate (1) sex-bias in frequency and distance of dispersal in this species, and (2) the effect of rainfall on fission–fusion dynamics of colonies.ResultsOur results demonstrate (1) that both males and females favour local dispersal but on rare occasions may disperse over distances greater than 400 m, (2) that males may disperse over greater distances than females, and (3) that males more frequently immigrate into established neighbouring colonies than females, who predominantly disperse by colony fission, i.e. multiple individuals “budding” from their native colony into a neighbouring territory, thereby establishing new colonies. Furthermore, our results demonstrate (4) elevated dispersal and colony fission in association with increased rainfall, supporting the hypothesis that rainfall may play a significant role in the maintenance and/or disruption of reproductive skew in Damaraland mole-rat populations.ConclusionThis study represents the first fine-scale spatial population genetic study in Damaraland mole-rats, and provides relevant insights into colony fission–fusion dynamics in a social and cooperatively breeding species.

Analysis of the Main Factors Affecting the Development of Human Capital as One of the Key Strategical Objectives in the Republic of Azerbaijan

Sustainable development is one of the most challenging and pressing challenges facing humanity. One of the driving factors of sustainable development is the successful development of human potential and the transformation of this potential into human capital. In recent decades, reproducible human capital has begun to occupy a significant share in the structure of the national wealth of many developed countries.&#x0D; In developed countries, the share of human capital in the country's national wealth reaches 70%, thereby significantly exceeding the importance of natural and physical capital in economic growth. Due to the variety of factors and conditions affecting the sustainable development of countries, the development of human potential and the formation of human capital around the world is happening with different dynamics. This largely depends on government priorities and policies in the field of full development of human potential, the creation of favorable social, economic and environmental conditions for its successful implementation. The author researches the factors that influence the development of human capital to varying degrees, analyzes various government policies aimed at the development of human capital, analyses experience of the public administration mechanisms in the Republic of Azerbaijan aimed at human development and the development of human capital. An important aspect of the success of the implementation of government programs is the assessment by influential international organizations of various country indicators. The article also highlights topical issues related to the development of human capital within the framework of national development priorities until 2030. The reforms carried out in the Republic of Azerbaijan in the field of vocational education, health care, demographic policy, the implementation of programs to support the private sector, especially small and medium-sized businesses, the creation of favorable conditions for investment in various sectors of the economy are important factors for the development of human capital in the medium and long term.&#x0D; The purpose of the article is to study the factors influencing the development of human capital in the Republic of Azerbaijan, to analyze the state measures carried out in the country aimed at creating the necessary conditions for the development of human capital.

First Report of Pseudomonas cichorii Causing Bacterial Leaf Spot on Romaine Lettuce (Lactuca sativa var. longifolia) and Escarole (Cichorium endivia) in New Jersey.

We previously reported an outbreak of bacterial leaf spot (BLS) caused by Pseudomonas cichorii occurring on sweet basil in New Jersey during the summer of 2018 (Patel et al. 2019), a growing season characterized by increased leaf wetness due to high humidity and unusually high levels of summer rains. Leaf spot was also observed, as a one-time event, on older mature leaves on romaine and escarole lettuce during that same year. Symptoms on escarole were observed as grayish brown-to-black concentric lesions on leaf parenchyma tissue, ranging from 1 mm to 1-2 cm in diameter. In more severely diseased samples, lesions coalesced to form larger necrotic areas giving a blight appearance. On occasion, infection was observed in leaf midveins as brownish gray necrosis. Symptoms on romaine lettuce were observed mostly as coalesced blackened lesions on leaf parenchyma tissue near margins with a rotted consistency that spread to the midvein in severe cases. Margins of leaf lesions were excised and macerated in sterile water before streaking onto Nutrient Agar (NA) and King's medium B agar (KMB) (Schaad et al. 2001). Growth on both NA and KMB were predominantly cream-colored circular bacterial colonies with undulated margins. Colonies on KMB fluoresced blue under 365nm UV light. Two representative colonies isolated from each host were selected for further characterization. All isolated tested negative for levan production, positive for oxidase, negative for potato rot, negative for arginine dihydrolase, and induced a strong hypersensitive response on tobacco within 24 h, consistent with LOPAT descriptions for P. cichorii (Lelliott et al. 1966). A single strain from each host (ESC6F2 and Rom1-1) was further characterized genetically to confirm species. PCR analysis using two primers sets: 16S rRNA gene universal primers 27F/1492R and Hcr1 primers used to amplify a 520 bp region of the pathogenicity gene cluster hrcRST in P. cichorii (Patel et al. 2019; Cottyn et al. 2011). Partial 16S rDNA gene sequences were deposited in the GenBank database for each isolate (ESC6F2: MT974180; and Rom1-1: MT982172). Sequence comparisons of ESC6F2 and Rom1-1 shared 99% identity with each other and several P. cichorii strains within the GenBank database, including strain B5-2-1 isolated from sweet basil in NJ the same year (MK501753). The partial hrcRST locus (strain ESC6F2: MW048775 and Rom1-1: MW048774) shared 100% identity to each other and strain B5-2-1 (MK507764), and 99% identity with P. cichorii strain P18-1 (MH396007) isolated from Ocimum basilicum in Hawaii. Koch's postulate was performed on escarole var. Full Heart and Romaine lettuce var. Ideal Cos to confirm pathogenicity of the isolated strains. Bacterial suspensions (1x107 cfu/ml) were syringe-injected (0.1 ml) into the leaf midribs, and pressure infiltrated into leaf parenchyma tissue of 3 plants. Control plants were inoculated with sterile water. Blackened necrosis developed within 72 h around bacteria-inoculation points, which expanded beyond inoculation points within a week. In contrast, control plants remained healthy and symptomless. Although significant crop loss occurred due to BLS on escarole and romaine lettuce, P. cichorii has not been isolated from diseased plant material since 2018. This suggests inoculum sources did not persist beyond 2018, or favorable environmental conditions for disease are inconsistent to cause noticeable damage to New Jersey crops.

Essential trace metals in plant responses to heat stress.

Essential trace metals function as structural components or cofactors in many proteins involved in a wide range of physiological processes in plants. Hence, trace metal deficiency can significantly hamper plant growth and development. On the other hand, excess concentrations of trace metals can also induce phytotoxicity, for example via an enhanced production of reactive oxygen species. Besides their roles in plant growth under favourable environmental conditions, trace metals also contribute to plant responses to biotic and abiotic stresses. Heat is a stress factor that will become more prevalent due to increasing climate change and is known to negatively affect crop yield and quality, posing a severe threat to food security for future generations. Gaining insight into heat stress responses is essential to develop strategies to optimize plant growth and quality under unfavourable temperatures. In this context, trace metals deserve particular attention as they contribute to defence responses and are important determinants of plant nutritional value. Here, we provide an overview of heat-induced effects on plant trace metal homeostasis and the involvement of trace metals and trace metal-dependent enzymes in plant responses to heat stress. Furthermore, avenues for future research on the interactions between heat stress and trace metals are discussed.

Assessment of the elements of the yield structure and the parameters of adapta-bility of varieties and hybrids of sunflower in the steppe Volga region

The article presents the results of the study of varieties and hybrids of sunflower bred by the Federal Agricultural Research Center for South-East Region in the steppe Volga region. As a result of two-factor analysis of variance, the contribution of factors to the overall variability of the studied indicators was revealed. It was found out that the elements of the yield structure are characterized by significant variability depending on the year, genotype and on the interaction of these factors. As a result of the research, a significant variation of the studied parameters of the sunflower was established. Factor A (variety) had the greatest influence on the anthode diameter - 33.57%; factor B (year) had the greatest influence on the number of seeds from one anthode (44.12%), the mass of 1000 seeds (40.61%); interaction of AB factors on the weight of seeds from one anthode (35.77%). Calculation of the regression coefficient of the yield of the studied varieties and hybrids of sunflower for varying environmental conditions made it possible to characterize their adaptability. It was found out that hybrids YuVS 3, Everest, Duet, Continent with a regression coefficient of more than 1.0 are characterized by the highest responsiveness to favorable environmental conditions. At the same time, the studied varieties (Skorospelyi 87, Saratovskiy 20, Saratovskiy 87, Stepnoy 81) have less variability in yield over the years of research, which confirms a more pronounced adaptability to unfavorable environmental conditions. In the conditions of the Right Bank of the Saratov Region, on average over three years, the highest yield of sunflower oilseeds had Saratovsky 20 variety (2.72 t/ha) and Continent hybrid (3.16 t / ha). The sunflower yield depended on the genotype (factor A) by 28.87 %, on the weather conditions of the year (factor B) by 49.26%. The interaction of the two factors was 19.68 %.