Phytopathogenic Micromycetes Research Articles

New Bacterial Strains of Рseudomonas laurentiana: Promising Agents for Agrobiotechnology

Bacterial strains ANT 17 and ANT 56, antagonistic to plant pathogenic fungi Bipolaris sorokiniana, were isolated from activated sludge. Physiological, biochemical, and culture morphological properties and analysis of the 16S rRNA gene sequence and composition of fatty acids of cell walls of strains ANT 17 and ANT 56 supported its classification as the species Pseudomonas laurentiana. It was shown that strains P. laurentiana ANT 17 and P. laurentiana ANT 56 possess a set of properties characteristic of PGP (plant growth-promoting) microorganisms: they exhibit antifungal activity against phytopathogenic micromycetes and are capable of decomposing phosphates and synthesizing phytohormonal substances. Inoculation of cucumber, tomato, and cabbage seeds had a beneficial effect on their germination. Presowing treatment of wheat seeds under conditions of a natural infectious background with an inoculum of the isolated bacterial strains contributed to a decrease in the spread of fungi that cause root rot. The possibility of using strains P. laurentiana ANT 17 and P. laurentiana ANT 56 in biotechnology in order to increase the productivity of agroecosystems is suggested. The ability to stimulate the growth and development of plants for P. laurentiana strains is shown for the first time.

Growth and development of phytopathogenic micromycetes under the influence of a mixture of essential oils

The creation a new biological preparations on based vegetable oils is a promising direction in improving the efficiency organic production a plant products in Ukraine. Their ecological expediency consists in safety for the person, environment, animals, entomophagous that gives the chance to receive ecologically safe production. It was studied the sensitivity a phytopathogenic fungi Fusarium graminearum, Alternaria alternata, Trichodérma víride to essential oils of basil and cinnamon. It is showed that the essential oils of basil and cinnamon are inhibit the growth, the development and sporulation phytopathogenic fungi Fusarium graminearum, Alternaria alternata, Trichodérma víride at an environmentally safe level. This indicates their high prospects in the creation the biological products for use in organic production, which will reduce the cost of plant raw materials and improve its quality.

Species composition of phytopathogenic micromycetes in seeds of cultural plants varieties

It is analyzed that the formation of pathogenic microbiome cultural plant is due to the interaction of populations of phytopathogenic micromycetes with plants of the variety as a biotic ecological factor in the formation of phytopathogenic background in agrophytocenoses of varieties cultural plant. The seeds of such promising varieties of cultural plant as soybeans (Kent and Suzirya), buckwheat (Son and Sophia), thistle (Riches) and yellow mustard (Forge) for micromycetes were analyzed. We carried out the analysis of seeds types of such cultural plant as soybean, buckwheat, thistle, mustard yellow on the location micromycetes and identified phytopathogenic fungi: Alternaria alternate Fr., Fusarium oxysporum Schleht, Cladosporium herbarum Lket Gray, Botrytis cinerea Pers. ex Fr., Ascochyta fagopyri Bres., Alternaria tenuissima (Kunze) Wiltshire, Aspergillus P. Micheliex Haller, Pénicillium Link., Mucor Micheliex F. It was determined that the species composition of phytopathogenic micromycetes in soybean and thistle seeds s is much more diverse compared with buckwheat and mustard yellow seeds. Among the identified micromycetes there are species with varying degrees of parasitism: obligate and facultative saprotrophs and parasites. To assess the typicality of the species and determine its position in the structure of dominance in the agrocenosis of cultivated plants, the criterion of the frequency of occurrence of the species was used. Fungi of genera Alternaria alternate, Fusarium oxysporumare characterized by different frequency of occurrence (11–30%). The seeds of Suzirya soybean variety and Son and Sophia buckwheat varieties are intensively inhabited by fungi of the genus Pénicillium (60–90%). We determined the indicator of similarity species composition of micromycetes withdrawn from seeds types of cultural plants by Jacquard similarity coefficient. It is established that seeds of soybeans and thistle as well as the seeds of thistle and yellow mustard are characterized with high level of micromycetes similarity (indicator of similarity — 75 and 66.7% respectively). At the same time, seeds of buckwheat and thistle as well as buckwheat and mustard yellow were characterized with low level of micromycetes similarity – 12.5 and 22.2%, respectively. The analyzed indicators provide an opportunity to evaluate seeds types of cultural plant in order to avoid ecological risks and biological pollution of agrocoenoses during sowing and cultivation of crops of different varieties.

Phytopathogenic micromycetes of the town of Kalinkovichi

As a result of the conducted researches in the territory of Kalinkovichi it was found 186 species of phytopathogenic fungi and fungus-like organisms, belonging to 4 divisions – Oomycota, Ascomycota, Basidiomycota and Deuteromycota. The detected micromycetes were parasitizing on 165 species of feeding plants from 45 families. The division of Ascomycota in the town of Kalinkovichi is represented by 70 species of 19 genera, the division of Basidiomycota – 32 species from 9 ge nera, the division of Deuteromycota – 47 species from 18 genera and the division of Oomycota – 37 species from 7 genera.

Изучение свойств штаммов бактерий рода Рaenibacillus, выделенных с семян нута

A necessary condition for the creation of effective biological preparations with a complex effect is the presence of bacterial strains that have several mechanisms of a positive effect on the plant. Preference is given to those microorganisms that are able to survive in adverse environmental conditions. The aim of the study was to search for new bacterial strains characterized by antagonism towards phytopathogenic microflora and exhibiting tolerance to soil contamination by lead ions and chloride ions. As a result of the screening, bacterial strains were isolated from the surface of chickpea seeds that were identified as Paenibacillus peoriae ANT 13 and Paenibacillus jamilae ANT 14 based on cultural-morphological and physiological-biochemical properties, as well as a comparative analysis of the nucleotide sequences of the gene 16S rRNA. The strains P. peoriae ANT 13 and P. jamilae ANT 14 exhibit antagonistic activity against phytopathogenic micromycetes. The strain P. jamilae ANT 14 is resistant to NaCl (content in the medium is up to 7 %), the strain P. peoriae ANT 13 is able to grow in the presence of Pb2 + ions in an amount up to 3150 mg/l. The use of isolated isolates for presowing treatment of wheat seeds (Triticum aestivum L.) helped to reduce the spread of root rot of seedlings and increase the length of shoots. Inoculation of seeds of alfalfa changeable (Medicago varia Mart.) of P. peoriae ANT 13 and P. jamilae ANT 14 increased the activity of nodulation and contributed to the growth of the root system of the plant, bacterization of chickpea seeds (Cicer arietinum L.) affected the increase in the mass of shoots and roots of this culture. The research results allow us to consider strains of P. peoriae ANT 13 and P. jamilae ANT 14 as promising objects of agricultural biotechnology.

Phytate-hydrolyzing rhizobacteria: abiotic stress tolerance and antimicrobial activity

Phytate-hydrolyzing bacteriaPantoeasp. 3.1, 3.2, 3.5.2, 3.6.1 andBacillus ginsengihumiM2.11 were previously isolated from the soil samples of the Republic of Tatarstan. The effect of cultivation conditions on the growth dynamics as well as antimicrobial activity was determined. All fourPantoeastrains showed optimum growth at 26 ºC and 28 ºC and pH 6.0-7.0. The optimum conditions for the growth ofB. ginsengihumiM2.11 strain was determined to be 26 ºC, 28 ºC and 37 ºC and alkaline pH 7 and 8. Salt concentration in the range of 0 to 1000 mM did not significantly affect the growth of the strains. Antagonistic activity ofPantoeasp. 3.5.2 was studied against phytopathogenic micromycetes, identified asAlternaria alternataandBipolaris sorokiniana. In the presence of bacterial isolate growth ofA. alternatawas inhibited by 57% and growth ofB. sorokiniana– by 85%. Minor growth inhibition byPantoeasp. 3.5.2 of gram-negative bacteria fromEnterobacteriaceaefamily was observed. The presence of fungicidal activity in thePantoeastrain together with its ability to hydrolyze soil phytates and overcome abiotic stress factors in soil can possibly serve as the basis for the new fungicide of microbial origin.

Microbiota of rhizosphere of peas under the influence of various technologies of crop cultivating

This article describes changes in the microflora depending on the variety of peas and its growing technologies. The microflora of rhizospheres of varieties Madonna and Starter under the influence of various technologies of cultivation of culture has been investigated. The risks of agroeconomy of peas during its vegetation are considered, which leads to increase in the number of phytopathogenic micromycetes in the rhizosphere of the plant. As a consequence, an increase in the spectrum of phytopathogenic fungi leads to the formation of epiphytoties that can accumulate toxins and mycotoxins. The development of epiphytotic species can lead to abrupt changes in the balance of its microbial and environmental pollution. Such violations substantially impair the composition of the soil. The systematic use of synthetic mineral fertilizers leads to depletion of the soil, changes in acidity, deterioration of functional bonds. Increased acidity of the soil prevents the activity of beneficial microorganisms, thus preventing the assimilation of leguminous crops of nitrogen resulting in impoverished soils. The degradation of soils is another negative consequence. The use of organic and biological technologies that increase and regulate microbial diversity in the rhizosphere of plant crops is an alternative methods. In addition, they do not pollute the environment. The regulating factor is an increase in saprotrophic fungi that inhibit the spread of pathogenic species. Saprotrophic species are involved in humus formation. The amount of phytopathogenic fungi in peas agrocenosis is substantially regulated by plants varieties and the technology of its cultivation. The changes of microbiodiversity of the rhizosphere, depending on the technologies of growing peas and varieties, are analyzed.

THE EFFICIENCY OF THE COMPLEX USE OF MICROBIAL FORMULATIONS AND FUNGICIDES FOR THE DISEASES CONTROL AND PRODUCTIVITY INCREASE OF VEGETABLE CROPS

The introduction of biotechnologies into the practice of land use, the reduction or replacement of chemicals by bioformulations, including microbial, are relevant for modern crop production. To date, a wide range of biological products based on soil bacteria has been developed, they are used to increase plant productivity and crop quality, protect plants from harmful organisms, and reduce the rate of mineral fertilizers and pesticides application. Aim. To study the effect of the complex use of microbial preparations Azotobacterin and Biophosphorin together with fungicides on the tomatoes, cucumbers, white cabbage diseases development and their productivity under field cultivation. Methods. Microbiological methods of micromycetes isolation from infected plants tissues; morphological and physiological methods of identification of phytopathogenic micromycetes of Alternaria, Pseudoperonospora and Fusarium genus; methods of field studies; methods of determination of diseases development and the effectiveness of protective action of biopreparations Azotobacterin (based on Azotobacter chroococcum ІМВ В-7171), Biophosphorin (based on Bacillus megaterium ІМВ В-7168) and fungicides Acrobat MC, Quadris 250 SC, Infinito 61 SC, Ridomil Gold MC 68 WG; statistical methods. Results. The bioformulation Azotobacterin and its composition with Biophosphorin in the mixtures with such fungicides as Acrobat MC, Quadris 250 SC, Infinito 61 SC, Ridomil Gold MC 68 WG with reduced consumption rates have provided a protective effect against pathogens at the level of fungicides with full consumption rates and the increase in yield of vegetable crops by 11–39% compared to control. Conclusions. Application of nitrogen-fixing and phosphate-mobilizing bacteria together with fungicides with the reduced consumption rates contributed to decrease of the tomatoes, cucumbers, white cabbage diseases control and increase in their yield, which makes possible to reduce the pesticide load on agrocenosis by an average of 17-33% and has significant environmental and economic importance.

New Bacillus subtilis Strains as Promising Probiotics

The properties of new B. subtilis strains GM2 and GM5, isolated from potato rhizosphere and possessing high antimicrobial activity, were studied. The potential of the strains for their use as probiotics was characterized. The strains were resistant to bile and to a wide range of the ambient pH. B. subtilis strains GM2 and GM5 possessed proteolytic and phytate-hydrolyzing activity and proved to be safe for model animals. The strains were characterized by antagonistic properties against phytopathogenic micromycetes, as well as against pathogenic and opportunistic enterobacteria. B. subtilis GM2 and GM5 were concluded to be promising strains for use as probiotics.

Influence of biologicaly active plant of kind solanaceae in phytopathogenic fungi

This work is important as the plant of kind Solanaceae have a number of factors phytoimmunity of complex biologically active substances. The influence on micromycetes biologically active substances of these plants is of interest, since the latter can serve as an alternative means of protecting plants from pathogens. Tasks thesis were to determine toxigenicity and phytotoxicity collection fungal strains, the allocation of biologically active substances from the nightshade and potato and study their effects on phytopathogenic micromycetes.

Phytopathogenic micromycetes in central Poland. I. Peronosporales and Erysiphales

The present paper begins a new series of studies investigating the occurrence of phytopathogenic micromycetes in Central Poland. Fungi of the orders Peronosporales and Erysiphalas are discussed in part one. Relevant knowledge on the subject is surveyed, and a list of published records (46 taxa) as well as the findings collected by the present authors (99 taxa) is provided. The list comprises 2 species new for biota of Poland - <i>Microsphaera deutziae</i> Bunkina and <i>Microsphaera elevata</i> Burrill, 10 rare and many common fungal species that had not been previously re00rded in this area as well as 21 plant taxa, mostly species of deliberate or accidental anthropogenic origin, that are new hosts of the parasites formerly listed in Poland.

Regularities in the Germination of Conidia of Phytopathogenic Fungi

The autoregulation of conidium germination in phytopathogenic micromycetes of the genera Fusarium, Botrytis, and Bipolaris was studied. It was shown that Trichoderma longibrachiatum was less competitive than Fusarium oxysporum after their simultaneous inoculation but inhibited the phytopathogen growth in the case of earlier introduction. In the latter case, no autoinhibition of the germination of F. oxysporum conidia occurred; moreover, a cooperative effect was observed, i.e., the number of germinated F. oxysporum conidia increased with an increase in their density.