Bacterial Diseases of Wheat in the Southern Ural: Manifestations, Biological Characteristics and Monitoring Features

The paper presents the results of a long-term monitoring of bacterial diseases of wheat in the steppe zone of the Southern Ural. A clear domination of the genus Xanthomonas over the genus Pseudomonas has been revealed (60 and 11% of the total samples collected, respectively). The frequency of a winter wheat infection with these two pathogens exceeded that of the spring wheat. The field phytosanitary assessment resulted in the observation of the earlier unknown manifestation of the Xanthomonas infection called as tip bacteriosis. The frequency of wheat infection with Xanthomonas sp. almost did not depend on the relief type, observation period, and sowing date, though the frequency of infection observed for the northern slope and lowland clearly exceeded those observed for other relief types. The frequency of infection with Pseudomonas sp. clearly depended on the sowing date and local relief type reaching the maximum at the lowlands (19–27%), so this relief type can be considered as a “signal” point for the early diagnostics of this pathogen

The health of soil ecosystem as self-maintenance and sustainable bioproductivity review article

In the review traditional characteristics of the soil quality are discussed. Soil health (SH) along with its soil quality and fertility, is considered as the most important, functional characteristic of any soil ecosystem (SE). The consistent patterns and results of the study of structure and functions of the microbial community (MC) of the soil ecosystem were generalized to substantiate the quantitative parameters of soil health. The author’s developments for definitions of soil and soil health are given. The prospects of using the parameters of SH for diagnostics at recovery and biological rehabilitation of technogenically disturbed soils are proposed

Some aspects of the distribution of Fusarium on cereals of Russia

Since 1995 the pathogens of genus Fusarium causing Root Rot, Snow Mold, Fusarium Head Blight of grain crops have been monitored in the Volga-Vyatka, Central, Central Chernozem and North Caucasian regions of the Russian Federation and in there were identified 15 Fusarium spp.: F. culmorum, F. heterosporum, F. sporotrichioides, F. oxysporum, F. nivale, F. graminearum, F. avenacеum, F. gibbosum, F. sambucinum, F. moniliforme, F. semitectum, F. poae, F. lateritium, F. solani, F. redolens. The high uniformity of Fusarium spp. has been revealed for the regions due to the susceptibility of crops to the soil-inhabiting micromycetes. Consistent long-term monitoring of the dynamics and frequency of occurrence of Fusarium spp. in a wide range of climatic areas has made it possible to characterize the state of the species of fungi in the regions and also to study their intraspecific and interspecific variability in toxicity and pathogenicity depended on biotic and abiotic factors. The prevalence of Fusarium spp. in the mycobiota has been determined by their plasticity and viability in the soil, on the weed roots and in the stubble of many crops and high competitive ability expressed pathogenicity and toxicity

Revealing the diversity of Fusarium micromycetes in agroecosystems of the North Caucasus plains for replenishing the State Collection of Phytopathogenic Microorganisms of the All-Russian Scientific Research Institute of a Phytopathology

In order to prevent crop yield losses from the most dangerous and economically important pathogenic organisms, it is necessary not only to monitor the virulence gene pool, but also to study the nature of pathogen variability and determine the potential for the emergence of new genes and races. This requires centralized collections of fungal cultures characterized by a set of stable strains to provide for phytopathological, immunological, breeding, genetic, toxicological, parasitological and other studies. The State Collection of Phytopathogenic Microorganisms of the ARSRIP is the State Depository of Phytopathogenic microorganisms that are non-pathogenic to humans or farmed animals. Currently, it has more than 4,500 accessions of plant pathogenic strains of fungi, oomycetes, bacteria, viruses, phytoplasmas, and the collection is updated annually. For this purpose, the study of the inter- and intraspecific genetic diversity of genus Fusarium was carried out in agricultural systems of the Krasnodar Territory. In 2020, the State Collection of Phytopathogenic Microorganisms was supplemented with 13 strains of Fusarium fungi isolated from tissues of winter wheat plants collected in several locations of the Krasnodar region. The complex of Fusarium fungi revealed on winter wheat usually included Fusarium oxysporum, F. culmorum, F. lolii, F. graminearum, F. fujikuroi, F. sporotrichioides, etc. The effect of the preceding crop on the frequency of Fusarium species isolated from winter wheat was observed. After series cloning of collected isolates, 21 strains of different fungal species characterized by stable morphology traits and known pathogenic and phytotoxic properties were selected for collection replenishment. Significant differences in pathogenic activity were revealed between fungi belonging to either the same or different species; the manifestation of this activity varied from the absence of any effect of spore suspensions on seedling development to a complete inhibition of their growth. The phytotoxic activity towards wheat seedlings varied from medium to high. Species possessing a high intensity of phytotoxic activities are the most dangerous for wheat, since they promote accumulation of dangerous phytotoxins in plant tissues

Bacterial diseases of wheat caused by Xanthomonas sp. in the Southern Ural: Identification issues

The identification of pathogenic agents isolated from infected wheat seeds and plants, collected in the Southern Ural and characterized by an atypical manifestation of bacterial infection (yellow leaf tips), has been carried out by direct microbiological and molecular methods. In addition, an indirect identification by the hypersensitive reaction (HR) approach has been performed simultaneously with the pathogenicity assessment of isolates using an indicator plant Plectranthus australis R. Br. Isolated samples have been microbiologically identified as Xanthomonas sp. According to the results of the PCR identification with species-specific primers, isolated samples represent Xanthomonas translucens; the reliability of the obtained results is corroborated by the hypersensitive reaction approach used also to assess the pathogenicity of isolates. Winter wheat, especially cv. Pionerskaya 23, where both X. translucens and Pantoea agglomerans were found, suffered more severe symptoms than spring wheat that was only affected by strains of X. translucens. To improve the reliability of the primary diagnostics of a bacterial character of seed infection, the provoking of the pathogen development by temperature or pH stress is proposed

ОЦЕНКА ЦИТОТОКСИЧНОСТИ ТРИХОТЕЦЕНА FUSARIUM SP. НА ЛИНИЮ РАКА МОЛОЧНОЙ ЖЕЛЕЗЫ IN VITRO

trichothecenes and their derivatives have recently attracted much attention of researchers with respect of their potential role in medicine, including for the treatment of different types of cancer. The purpose of the study was to investigate the cytotoxic effect of Fusarium trichothecene on human breast cancer cells,  human skin fibroblasts and embryonic kidney cells in vitro. Material and methods. Based on the Mtt assay, the cytotoxic effect of trichothecene on cell cultures was determined. Evaluation of morphological changes in cell cultures under the influence of trichothecene was performed by light microscopy. Results. Fusarium trichothecene was found to exhibit a dose-dependent toxic effect on cell lines in the range 1 nM to 1000 nM. the most pronounced cytotoxic effect of trichothecene was observed in human breast cancer cell line (IС50 94.72 ± 4.1 нМ). Lower doses of trichothecene led to a change in the size, shape of human breast cancer cells, human skin fibroblasts and embryonic kidney cells, and loss of contact between them and their isolation. the degradation of cell membranes, formation of unformed cell aggregates and fragments were observed in higher doses of trichothecene. Conclusion. Fusarium trichothecen is a biologically active compound and is less toxic to the normal than to the cancer cell lines, therefore, further studies of this agent are needed.В последнее время трихотеценовые соединения и их производные привлекают внимание исследователей в связи с их потенциальной возможностью применения в медицине, в том числе для лечения различных видов рака. Цель исследования – изучение цитотоксического действия трихотецена Fusarium sp. в отношении линий опухолевых клеток рака молочной железы, нормальных клеток фибробластов кожи и почек эмбриона человека in vitro. Материал и методы. С использованием общепринятого метода МТТ-теста проводилось определение цитотоксического действия трихотецена в отношении исследуемых культур клеток. Оценку изменения в морфологии клеток под воздействием трихотецена проводили методом световой микроскопии. Результаты. Было обнаружено, что трихотецен Fusarium sp. в диапазоне концентрации 1–1000 нM проявлял дозозависимое токсическое действие в отношении исследуемых линий клеток. Наиболее выраженное цитотоксическое действие трихотецена наблюдали при его действии на линию опухолевых клеток молочной железы (IС50 94,72 ± 4,1 нМ). Совместная инкубация трихотецена с линиями клеток рака молочной железы, клеток фибробластов кожи и почек эмбриона человека в более низких дозах приводила к изменению размеров, формы клеток, потере контактов между ними и их обособлению. При более высоких дозах трихотецена наблюдалась деградация мембран, образование неоформленных клеточных агрегатов и фрагментов (апоптозных тел). Заключение. Трихотецен Fusarium sp. обладает биологически активным потенциалом и является менее токсичным по отношению к нормальным клеткам человека по сравнению с опухолевыми, поэтому его целесообразно в дальнейшем исследовать как возможного противоопухолевого агента

Выращивание Ipomoea batatas (L.) Lam. в условиях светокультуры in vitro и ex vitro

Relevance. Currently, food products that include prebiotics, in particular, inulin, are particularly popular. Interest in this substance is justified by its valuable properties – it is a good immunomodulator, cleanses the body of toxins, radionuclides, "bad" cholesterol, promotes the assimilation of useful trace elements necessary for human life. Inulin is contained in plants such as jerusalem artichoke, chicory, as well as in sweet potatoes, the popularity of which is increasing every year. However, sweet potato plants are afraid of cold and frost-resistant. Therefore, the creation of new varieties and hybrids that are resistant to low temperatures is an urgent problem. Cellular biotechnology is aimed at solving this problem using methods of clonal microreproduction, cell selection, somatic hybridization, etc. For rapid reproduction and obtaining high-quality planting material, biotechnology methods are used, in particular, clonal micro-propagation. However, in this technology there are difficulties associated with poor adaptation of microclones to ex vitro conditions. This fact introduces an additional requirement for the selection of optimal rooting modes in vitro and ex vitro adaptation of microclones.Material and methodology. The aim of the work was to study the influence of cultivation conditions on in vitro rooting and ex vitro adaptation of I. batatas (L.) microclones. The object of the study was sweet potato microgears propagated in vitro. I. batatas micro-gears were cultured in vitro on a Murashige-Skug medium, differing by the type of auxins. The influence of red (R) and far red (FR) light on the shoots rooting in vitro and the adaptation of microclones ex vitro was studied.Results. It has been experimentally established that the cultivation of micro-gears on a medium containing indolyl butyric acid at a concentration of 0.5-1 mg/l and under conditions of illumination by LED lamps of red and far red light in equal amounts leads to the production of microclones with a well-developed root system and vegetative biomass. The use of an aeroponic installation at the last stage of clonal micro-propagation makes it possible to obtain high-quality planting material that can adapt well to open ground conditions.Актуальность. В настоящее время особой популярностью пользуются продукты питания, в состав которых входят пребиотики, в частности, инулин. Интерес к данному веществу оправдан его ценными свойствами – он является хорошим иммуномодулятором, очищает организм от токсинов, радионуклидов, «плохого» холестерина, способствует усвоению полезных микроэлементов, необходимых для жизнедеятельности человека. Инулин содержится в таких растениях, как топинамбур, цикорий, а также в батате, популярность которого с каждым годом возрастает. Однако растения батата боятся холода и неморозоустойчивы. Поэтому создание новых сортов и гибридов, обладающих устойчивостью к пониженным температурам является актуальной проблемой. Клеточная биотехнология направлена на решение данной проблемы с применением методов клонального микроразмножения, клеточной селекции, соматической гибридизации и др. Для быстрого размножения и получения высококачественного посадочного материала применяют методы биотехнологии, в частности, клональное микроразмножение. Однако в этой технологии существуют трудности, связанные с плохой адаптацией микроклонов к условиям ex vitro. Этот факт вносит дополнительное требование к подбору оптимальных режимов укоренения in vitro и адаптации ex vitro микроклонов.Материал и методика. Целью работы было изучение влияния условий культивирования на укоренение in vitro и адаптации ex vitro микроклонов I. batatas (L.). Объектом исследования были микрочеренки батата, размноженные in vitro. Микрочеренки I. batatas культивировали in vitro на питательной среде, содержащей минеральные соли по прописи Мурасига и Скуга, а также различные ауксины. Изучали влияние красного (R) и дальнего красного (FR) света на укоренение микропобегов in vitro и адаптацию микроклонов ex vitro.Результаты. Экспериментально установлено, что выращивание микрочеренков на питательной среде, содержащей ИМК в концентрации 0,5-1 мг/л и в условиях освещения светодиодными лампами красного и дальнего красного света в равном соотношении, приводит к получению микроклонов с хорошо развитой корневой системой и надземной биомассой. Применение аэропонной установки на последнем этапе клонального микроразмножения позволяет получать высококачественный посадочный материал, способный хорошо переносить адаптацию к условиям открытого грунта