109 research outputs found

    Biochemical responses of 5 buckwheat (Fagopirum esculentum Moench.) cultivars to seed treatment by Azospirillum brasilense

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    Cultivation condition have a large effect on efficiency of buckwheat. Drought, high temperatures and their fluctuations, salinity, oxygen deficit in the soil, ultraviolet radiation, and abnormal nutrient content in the soil are the most common reasons of decreasing productivity of plants. Suboptimal parameters of the cultivation technology can also cause abiotic stress. Plant can decrease its efficiency from 30% to 50% depend on stress conditions. Using bacterial cultures is one of the preventive approaches to overcoming the negative impact of stressors. Microorganisms produce biologically active substances that stimulate plant growth, increase their resistance to abiotic factors. They are growth regulators and long-acting anti-stressants as well. Malondialdehyde (MDA) is formed as a result of the oxidative degradation of polyunsaturated fatty acids. Fructans are polysaccharides that are derived from D-fructose residues found in higher plants, green algae and bacteria. Fructans are involved in the adaptation of plants to the action of abiotic stressors and are valuable nutrients. The effect of Azospirillum brasilense pre-sowing treatment of buckwheat seeds on physiological and biochemical processes of MDA and fructan content was researched. Seed treatment with Azospirillun brasilense reduced the content of MDA in Ukrayinka and Syn 3/02. Sofia and Olga had a low level of MDA, but seed treatment increase it. Seed treatment increased the efficiency of photosynthesis (Fv / Fm) in Syn 3/02 from 0.58 to 0.72; in other varieties this effect was negligible. All cultivars have a strong relation between MDA and fructan content, that shows their participation in responses on cultivation conditions. Efficiency of photosynthesis in flowering–seed formation stage (BBCH 65–75) was close to maximum in field condition(0.70 ± 0.05) and seed treatment can increase it

    Efficacite agronomique du compost a base de la biomasse du « neem » et de l’anacarde sur des cultures maraicheres dans la zone des Niayes au Senegal

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    Dans la zone des Niayes au Sénégal, les sols sont pauvres en matières organiques et en éléments nutritifs nécessaires aux plantes. Les engrais chimiques utilisés pour améliorer les rendements ont engendré une forte pollution des sols et de la  nappe phréatique. L’objectif de cette étude est d’évaluer la valeur agronomique du compost fabriqué à base des feuilles de neem et d’anacarde, de fiente de volaille et de la cendre de bois. Le compost obtenu présente un rapport C/N de 15,49 et des teneurs en N - P - K de 9,1, 14,8 et 7,3 mg/kg, respectivement. Les différentes doses du compost testées  sur  des  cultures  maraichères  ont  révélé  des  performances  agronomiques  meilleures par rapport aux témoins. La dose T3 (30 t/ha) a induit les meilleurs rendements pour la tomate (27,213 t/ha) et l’oignon (105,263 t/ha). Pour le chou et la pomme de terre, la dose T1 (10 t/ha) a permis d’obtenir les meilleurs rendements (144,533 t/ha et 55,163 t/ha, respectivement). Par contre pour le poivron, la dose T2 (20 t/ha) a favorisé les meilleurs rendements (32,534 t/ha) avec un poids moyen (81,748g) et un nombre de fruits/récolte considérablement plus élevé. Ce compost pourrait constituer une alternative réelle à l’utilisation abusive de l’engrais minéral dans la zone agricole des Niayes.Mots clés : Compost, Neem, Feuilles d’anacarde, Maraichage, Sénéga

    Nanopreparations in technologies of plants growing

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    Received: December 1st, 2020 ; Accepted: March 25th, 2021 ; Published: March 30th, 2021 ; Correspondence: [email protected] use of engineered nanomaterials in sustainable agriculture has demonstrated a completely new way of food production that can potentially overcome uncertainty in the agricultural sector with limited available resources. Nanoparticle engineering is one of the latest technological innovations which demonstrate unique target characteristics. During 2013–2020, research on the directions and effectiveness of nanopreparations in plant growing: nutrient source, activation of photosynthesis, immunocorrectors, stimulators of seed germination, plant growth and development, multivalent drugs for increasing plant resistance to stress was conducted. Monoparticles, nanoparticle combinations, and chelate complex of nano fertilizers on crops of soybean were tested. Field research was conducted in a stationary field experiment of the Plant Science Department of the National University of Life and Environmental Sciences of Ukraine. The soil of the stationary experiment is typical chernozem. In research was used soybean (Glycine max (L.) Merr.) of early-ripening variety Horol. Over the years of research, weather conditions varied, but were within the typical for zone of research. Average monthly temperatures were close or higher the perennial average indicators. The purpose of the research is to find out the influence of pre-sowing seed treatment and fertilizing of crops by nano-preparations Avatar (microfertilizer of carboxylates of natural acids), Iodis-concentrate (immunomodulator - stimulator of growth processes), and Super Micro Plus (nanochelate fertilizer) on leaf formation - rate, the activity of symbiotic nitrogen fixation and yield of soybean variety Horol. Nanopreparations were used for pre-sowing seed treatment and fertilizing - spraying during the growing season in several doses. The use of nanopreparations, as seed treatment in combination with inoculation and as fertilizer, intensified formation of the leaf surface area, symbiotic apparatus activity of soybean plants. The introduction of nanofertilizers complex in the top-dressing helped to increase yields and change the functional quality of crop products which indicates their unconditional effectiveness. Soybean yield significantly depended on weather conditions, varying from 1.23 to 3.48 t ha-1 depending on the weather conditions and the combination of seed inoculation and nanofertilizer. Soybean yield under favourable weather conditions in 2016, depending on the use of preparation combination ranged from 2.27 to 3.48 t ha-1 . As a result of the research, it was found that the use of nanopreparations Avatar, Jodis-concentrate and Super Micro Plus for seed treatment and fertilizing intensified leaf surface formation and symbiotic apparatus activity of soybean plants. The obtained results confirm that application of nanofertilizers complex Jodis-concentrate, Avatar and nano chelate fertilizer Super Micro Plus in the soybean fertilizing helped to increase the yield, which testifies to their unconditional effectiveness. The highest efficiency of nanofertilizers was shown by inoculation and seed treatment by Avatar and fertilizing by Avatar + nano chelate fertilizer Super Micro Plus, providing the formation of 52.4 thousand m2 ha-1 of leaf surface area of soybean varieties Horol, 69.7 pcs per plant of root nodules, 785 mg per plant of their weight and yield at the level of 2.79 t ha-1 an average of five years

    Anthropogenic communication of the Cherkasy oblast as an ecosystem-forming component of the region modern landscape structure

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    Purpose. To investigate the anthropogenic communication of the Cherkasy oblast as an ecosystem-forming component of the modern landscape structure of the area of research. Research materials and methods. Methods. On the principle of natural-anthropogenic coexistence general scientific and specific scientific research methods were applied. Results. The peculiarities of natural conditions and natural resources are determined by the geographical location within the borders of the Dniester-Dnieper and Left Bank-Dnieper forest-steppe regions of the East European plain country. The class of road landscapes of the study area is formed by the following types of roads, namely: automobile, dirt, forest and field roads, railways. In the landscape structure of Zvenyhorod district, the length of highways, unpaved roads, field and forest roads, railways. Uman district and Cherkasy district have the highest index of connectivity in terms of road length. The lowest indicators of the index of communication in terms of the length of highways in Zolotoniskyi district. Uman district has the highest index of communication in terms of the length of dirt roads, and Zvenigorodsky district has the lowest. Zolotoniskyi district and Cherkasy district have the highest index of communication in terms of the length of field and forest roads. The lowest indicator is Zvenigorodsky district, Uman district. Cherkasy district has the highest communication index in terms of railway length and Zvenigorodsky district has the lowest. Conclusions. The Zolotonisky district of Cherkasy region has the highest index of general anthropogenic communicability, i.e. it has the highest degree of anthropogenic transformation of the territory and anthropogenic loa

    Геоботанічні аспекти екотонізації природних ландшафтів

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    Vegetation is one of the main criteria for landscape differentiation of the Earth surface. The main morphological feature of the landscape is the presence or absence of the forest that is, and the gradual character of the boundaries between the natural zones causes the formation of fairly wide transitional zones bands – ecotones. They have become one of the most common subjects in landscape research in recent years. This is natural in view of the insufficient localization of ecotones and their constant drift in the light of gradual changes in climate and degradation of soil cover. In modern studies, structural-geographical ecotones are considered not as clear sharp boundaries, but as rather wide transitional bands. There are four natural zones (mixed coniferous-deciduous forests, deciduous forests, forest-steppe and steppe) and three structural and geographical strips – pasture, forest and field districted in the plain part of Ukraine. If the physical-geographical boundary of the forest-steppe and steppe is traditionally drawn along the Balta – Kropyvnytskyi – Dnipro – Izyum – Kup'yansk line, from the standpoint of constructive geography, the area of continuous predominance of the field landscapes is shifted to the north by almost 100 km. In general, the territory of the traditionally separated southern sub-zone of the forest-steppe objectively reaching the steppe zone is today. Anthropogenic factor makes its adjustments to the holding of ecotones, in particular through deforestation. The action of natural and anthropogenic factors is synergistic. On the one hand, the natural process of the steppe on the forest continues; on the other hand, one actively promotes deforestation. Therefore, the boundaries of Polissya and the Forest-Steppe are becoming less clear. Ecotones are manifested not only on the interzonal (macro- and meso scale) but also on the intra-zonal, within landscape complexes (micro levels). A striking example would be the ecotones in forest landscapes. In general, the continuous changes of the landscape environment, caused nowadays by both natural and anthropogenic factors, inevitably cause the displacement of both geobotanical and physical-geographical boundaries. However, most landscape systems are not homogeneous in their typological characteristics; the transitions between them are rather blurred. This further complicates the boundaries and suggests the leading importance of ecotones in the terrestrial landscape organization.Відзначено, що більшість сучасних ландшафтів – як натуральних природних, так і антропогенних – мають характер екотонів. Наголошено, що екотонізація виразно позначається на педобіогенному компоненті-чинникові ландшафту. Зауважено, що формування екотонів відбувається як на макро- й мезо-, так і на мікрорівні організації рослинного компоненту. Проілюстровано, що явище поступового переходу від однієї фізико-географічної зони до іншої яскраво проявляється на прикладах лісостепу Правобережної України – як у межах екотону "зона мішаних лісів" – "лісостеп", так і в смузі екотону "лісостеп" – "степ". Наголошено, що процесам екотонізації ландшафтів істотно сприяє втручання антропогенного чинника. Розглянуто різні варіанти екотонізації лісових фітоценозів, зокрема висвітлено особливості природних і антропогенних екотонів "ліс – галявина", "ліс – прогалина", "ліс – узлісся", "ліс – зруб" тощо. Відзначено високий рівень біорізноманіття, властивий лісовим ландшафтам завдяки їхній екотонізації. Проаналізовано феномен "екотону в часі", що проявляється на сукцесійних стадіях розвитку лісових фітоценозів. Окреслено основний зміст концепцій змін порід деревної лісової рослинності відповідно до поглядів В. П. Кучерявого та Г. Ф. Морозова. Зауважено, що сукупна дія природних і антропогенних чинників увиразнює розмитість меж природних регіонів і в такий спосіб підсилює екотонізацію ландшафтів, зокрема лісових. Наголошено, що дослідження екотонів становить комплексну міждисциплінарну наукову проблему, що перебуває на пограниччі географії, геоботаніки, лісознавства, ландшафтної та соціоекології

    Changes in the Molecular Epidemiology of Pediatric Bacterial Meningitis in Senegal After Pneumococcal Conjugate Vaccine Introduction.

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    BACKGROUND: Bacterial meningitis is a major cause of mortality among children under 5 years of age. Senegal is part of World Health Organization-coordinated sentinel site surveillance for pediatric bacterial meningitis surveillance. We conducted this analysis to describe the epidemiology and etiology of bacterial meningitis among children less than 5 years in Senegal from 2010 and to 2016. METHODS: Children who met the inclusion criteria for suspected meningitis at the Centre Hospitalier National d'Enfants Albert Royer, Senegal, from 2010 to 2016 were included. Cerebrospinal fluid specimens were collected from suspected cases examined by routine bacteriology and molecular assays. Serotyping, antimicrobial susceptibility testing, and whole-genome sequencing were performed. RESULTS: A total of 1013 children were admitted with suspected meningitis during the surveillance period. Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus accounted for 66% (76/115), 25% (29/115), and 9% (10/115) of all confirmed cases, respectively. Most of the suspected cases (63%; 639/1013) and laboratory-confirmed (57%; 66/115) cases occurred during the first year of life. Pneumococcal meningitis case fatality rate was 6-fold higher than that of meningococcal meningitis (28% vs 5%). The predominant pneumococcal lineage causing meningitis was sequence type 618 (n = 7), commonly found among serotype 1 isolates. An ST 2174 lineage that included serotypes 19A and 23F was resistant to trimethoprim-sulfamethoxazole. CONCLUSIONS: There has been a decline in pneumococcal meningitis post-pneumococcal conjugate vaccine introduction in Senegal. However, disease caused by pathogens covered by vaccines in widespread use still persists. There is need for continued effective monitoring of vaccine-preventable meningitis

    Phylogeography and resistome of pneumococcal meningitis in West Africa before and after vaccine introduction

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    Despite contributing to the large disease burden in West Africa, little is known about the genomic epidemiology of Streptococcus pneumoniae which cause meningitis among children under 5 years old in the region. We analysed whole-genome sequencing data from 185 S. pneumoniae isolates recovered from suspected paediatric meningitis cases as part of the World Health Organization (WHO) invasive bacterial diseases surveillance from 2010 to 2016. The phylogeny was reconstructed, accessory genome similarity was computed and antimicrobial-resistance patterns were inferred from the genome data and compared to phenotypic resistance from disc diffusion. We studied the changes in the distribution of serotypes pre- and post-pneumococcal conjugate vaccine (PCV) introduction in the Central and Western sub-regions separately. The overall distribution of non-vaccine, PCV7 (4, 6B, 9V, 14, 18C, 19F and 23F) and additional PCV13 serotypes (1, 3, 5, 6A, 19A and 7F) did not change significantly before and after PCV introduction in the Central region (Fisher's test P value 0.27) despite an increase in the proportion of non-vaccine serotypes to 40 % (n=6) in the post-PCV introduction period compared to 21.9 % (n=14). In the Western sub-region, PCV13 serotypes were more dominant among isolates from The Gambia following the introduction of PCV7, 81 % (n=17), compared to the pre-PCV period in neighbouring Senegal, 51 % (n=27). The phylogeny illustrated the diversity of strains associated with paediatric meningitis in West Africa and highlighted the existence of phylogeographical clustering, with isolates from the same sub-region clustering and sharing similar accessory genome content. Antibiotic-resistance genotypes known to confer resistance to penicillin, chloramphenicol, co-trimoxazole and tetracycline were detected across all sub-regions. However, there was no discernible trend linking the presence of resistance genotypes with the vaccine introduction period or whether the strain was a vaccine or non-vaccine serotype. Resistance genotypes appeared to be conserved within selected sub-clades of the phylogenetic tree, suggesting clonal inheritance. Our data underscore the need for continued surveillance on the emergence of non-vaccine serotypes as well as chloramphenicol and penicillin resistance, as these antibiotics are likely still being used for empirical treatment in low-resource settings. This article contains data hosted by Microreact
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