Refine search
Results 1-3 of 3
ATTENTION FOR ONION BREEDERS: BLACK MOLD CAUSED BY ASPERGILLUS NIGER TIEGHEM
2012
A. F. Agafonov | L. T. Timina | K. S. Shestakova
The black mold of several varieties of onion was found in our zone of cultivation. The causative agent was identified as Aspergillus niger Tieghem 1867. The degree of damage by this disease grades and depends on temperature optimal for growth and sporulation of fungi.
Show more [+] Less [-]The allocation of carbohydrates from vegetable raw materials and their identification with the use of capillary electrophoresis
2019
Stanislav I. Biryulin | Nataliya E. Posokina | Marina V. Trishkaneva
Relevance. Carbohydrates are integral components of the cells and tissues of all living organisms of the plant and animal world; they are important components of the plant cell walls, as well as the extracellular matrix of animal and human tissues. The type of monosaccharide composition of polysaccharides determines their biological functions for the organism. However, it is difficult to establish the relationship between the structure of the carbohydrate molecule and its biological function.Methods. In this article, the author provides an overview of methods for identifying the monosaccharide composition of plant polymers by capillary electrophoresis, in order to optimize the sample preparation procedure and the conditions of analysis. A scheme for the stepwise release of polysaccharides from raw materials is given: the isolation of soluble monosaccharides and polysaccharides, the extraction of the pectin fraction, the extraction of cellulose and hemicelluloses, in order to study the composition of each fraction. A procedure for acid hydrolysis of polymers to monosaccharides using oxidizing agents such as sulfuric and trifluoroacetic acid is described. In the final part of the article, three different schemes for the identification of the monosaccharide composition were analyzed, namely, separation of the components under strongly alkaline conditions, preliminary derivatization with 1-phenyl-3-methyl-5-pyrazolone, preliminary preparation of (S) (-) α-methylbenzylamine S-PEA) derivatives.Results or Findings. An analysis of the literature shows that the composition of polysaccharides is widely studied by various methods. At the same time, a number of problems remain associated with the implementation of these methods in terms of sample preparation and identification of all monosaccharides characteristic of the studied raw materials. The method of capillary electrophoresis can solve some of these problems; however, little has been studied. The study of carbohydrates in plant objects begins with the procedure for extracting carbohydrates (polysaccharides and monosaccharides) from the plant matrix, hydrolysis of polysaccharides, and subsequent identification using the CE method. The optimization of this scheme of the CE method for determining the composition of polysaccharides is an urgent scientific task.
Show more [+] Less [-]Identification of pathogenic fungi in garlic bulbs during storage and in the root zone during plant growth | Идентификация патогенных грибов в луковицах чеснока при хранении и в корневой сфере в период роста растений
2021
Filyushin, M.A. | Danilova, O.A., Russian Academy of Sciences, Moscow (Russian Federation). Federal Research Centre Fundamentals of Biotechnology | Seredin, T.M., Federal Research Center of Vegetable Crop Selection, Moscow Region (Russian Federation)
Потери урожая с.-х. культур связаны не только с развитием болезней в процессе вегетации, но и при послеуборочном хранении. Чеснок является популярной овощной и пряно-ароматической культурой во многих странах мира. Значительные потери урожая чеснока при выращивании и хранении связаны с грибными патогенами, наиболее вредоносными из которых являются представители р. Fusarium. В Московской области поражение посевов чеснока фузариозом проявляется ежегодно, но с различной интенсивностью. В Федеральном научном центре овощеводства было показано, что гнили и увядание растений чеснока вызывается комплексом патогенных грибов, включающим преимущественно различные виды Fusarium. При этом соотношение видов Fusarium в патогенном комплексе изменяется от года к году, регистрируются новые виды Fusarium и их расы. Цель работы - определение грибных фитопатогенов, вызывающих сухую гниль зубков чеснока при послеуборочном хранении. Для проведения работы из хранилища были взяты луковицы чеснока сортов Дубковский и Стрелец. В результате визуального осмотра были выявлены зубки с симптомами сухой гнили. Пораженные ткани зубков были помещены на картофельно-декстрозный агар для получения грибных колоний. Анализ морфолого-культуральных признаков грибных изолятов, а также нуклеотидных последовательностей 4 участков ДНК (спейсеры ITS, гены EF1а, RPB1 и RPB2) показал, что возбудителем сухой гнили зубков чеснока является патогенный гриб Fusarium proliferatum. Дополнительно в полевых условиях была проведена идентификация на основе анализа последовательностей спейсеров ITS и гена EF1а фитопатогенных грибов, обитающих в ризосфере растений чеснока. В результате были обнаружены 2 вида грибов р. Fusarium (F. proliferatum и F. oxysporum f. sp. сepae), а также виды Rhizoctonia solani, Volutella rosea и Ceratobasidium sp. | Crop yield losses are associated not only with disease ocurence during the growing season, but also during post-harvest storage. Garlic is a popular vegetable and aromatic crop in the world. Significant losses in garlic yield during cultivation and storage are associated with fungal pathogens, the most harmful of which are representatives of the genus Fusarium. In the Moscow region, the garlic crops are affected by Fusarium annually, but with varying intensity. At the Federal Scientific Vegetable Center (FSVC), it was shown that rot and wilting of garlic plants is caused by a complex of pathogenic fungi, including mainly different Fusarium species. At the same time, the ratio of Fusarium species in the pathogenic complex changes from year to year, new Fusarium species and their races are registered. The aim of this study was to identify fungal phytopathogens causing dry rot of garlic cloves during post-harvest storage. To carry out the work, garlic bulbs of cultivars 'Dubkovsky' and 'Strelets' were taken from the FSVC storage. As a result of visual examination, cloves with symptoms of dry rot were identified. The diseased cloves tissues were plated on potato dextrose agar to obtain fungal colonies. Analysis of the morphological and cultural characteristics of fungal isolates, as well as the nucleotide sequences of four DNA regions (ITS spacers, genes EF1alpha, RPB1, and RPB2) showed that the causative agent of dry rot of garlic cloves is the pathogenic fungus Fusarium proliferatum. In addition, in the field, identification was carried out based on the analysis of the sequences of spacers ITS and the EF1 alpha gene of phytopathogenic fungi inhabiting the root zone of garlic plants. As a result, two species of fungi of the genus Fusarium (F. proliferatum and F. oxysporum f. sp. cepae), as well as the species Rhizoctonia solani, Volutella rosea, and Ceratobasidium sp. were found out there.
Show more [+] Less [-]