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Ermolova V.P.,Federal Agency of Scientific Organizations
Sel'skokhozyaistvennaya Biologiya | Year: 2016

Recently crystal-forming bacilli of thuringiensis group are considered the main microbial producers of insecticides. For these bacilli the high adaptability is characteristic leading to wide distribution of these anaerobic spore-forming bacteria in nature. The same Bacillus thuringiensis subspecies and variants were isolated on different continents regardless the presence and prevalence or absence of the host insects of this entomopathogen. In different countries and regions the researchers are searching for new B. thuringiensis isolates. In the paper the data are represented on B. thuringiensis isolation from natural substrates in the territory of Leningrad province. A total of 24 samples of soil, litter, water, silt, sick and died insects have been collected. The samples were cultivated on fish agar. Among more than 3,000 colonies, 62 ones with specific morphology were found. By microscopy with black aniline dye a total of 12 isolates of 62 isolates tested were found out to form both spores and differently shaped crystals of the endotoxin. The microorganisms were selected with regard to entomocidal and larvicidal activity and identified using H. De Barjac, A.A. Bonnefoi (1968) and O. Lysenko (1985) schemes. The investigation made it possible to classify isolates as B. thuringiensis of?1 (var. thuringiensis, isolates NoNo 12, 20, 40, 41),?3a3B (var. kurstaki, isolates NoNo 15, 29, 49) and?14 (var. israelensis, isolates NoNo 14, 25, 33, 38, 44) serovars. With regard to biological properties (production of acetyl methyl carbonate, lecithinase, pigment, p-exotoxin; pellicle in broth culture; sucrose, mannose, cellobiose, salicin fermentation; starch degradation; proteolytic activity) these isolates are close to standard strains. Isolates are characterized by high productivity, entomocidal and larvicidal activity and can be used as producers of biologicals against insects and larvae. In the isolates of BtH1, BtH3a3b and BtH14 serovars the titers varied as 2.42×109-2.78×109; 1.85×109-2.15×109 and 2.65×109-3.28×109 CFU/ml, respectively. The activity against Leptinotarsa decemlineata Say larvae in isolates NoNo 12, 41 of the BtH1 serovar was the same as in standard strain BtH1 with LD50 at 0.19 %. Entomocidal activity of the isolates NoNo 15, 29 and 49 of the BtH3a3b serovar expressed as LD50 for Ephestia kuehniella of the 2nd instar was 0.88; 0.82 and 0.92 %, respectively, while in the standard strain BtH3a3b the LD50 was 0.86 %. In the isolates NoNo 33, 44 of the BtH11 serovar the titer was the same as in the standard strain, and the activity was even higher compared to the standard. In the isolates NoNo 33, 44 the LD50 for the 4th instar Aedes aegypti larvae was 0.17×10-3 and 0.16×10-3 %, respectively, when in standard strain BtH14 it was 0.18×10-3 %. Thus, a total of 12 of the isolates which have been identified as B. thuringiensis are close to the type isolates on their biological characteristics and promising as producers of biologics with insecticidal action. Source


Kruglov Yu.V.,Federal Agency of Scientific Organizations
Sel'skokhozyaistvennaya Biologiya | Year: 2016

Study of the taxonomic and functional diversity of soil microorganisms association is of great theoretical significance for understanding the structure of the soil microbial community, the nature of the interaction of individual species of microorganisms belonging to this community, as well as their participation in the processes of soil formation and circulation of substances. This article summarises a brief history of ideas about the functioning of soil microbial complex, providing transformation and mineralization of organic matter in soil formation processes. Soil as habitat for microorganisms is heterogeneous that defines microzonal character of the distribution and activity of microorganisms that live in it. The structure of the association of microorganisms and its physiological profiles vary in time and space (D.G. Zvyagintsev, 1987). This defines methodological difficulties and the significant variability of the results of the evaluation of soil microflora by various authors. This review discusses the methodological approaches in determining the physiological diversity of soil microorganisms association. Traditional methods of elective culture media in over a century allowed to reveal numerous physiological groups of microorganisms and developed an idea about their role in the cycle of matter, processes of soil formation and plant nutrition. However, such work is almost not given anything new in principle, both in environmental studies, as well as in agronomy over the past 20 years. At the end of the 1990s a method of analysis of the carbon source utilization profiles (SUP) of natural microorganisms association by BIOLOG system used previously only in medical and general microbiology was proposed to study the physiological diversity for the test strain (J.L. Garland, A.L. Mills, 1991). This approach was further developed by H. Insam (1997), M.V. Gorlenko and P.A. Kozhevin (2005) and others. A number of modifications of this method (Eso-Plates, ECOLOGY and others) characterized by a set of organic substrates, which, as the authors suggest, is most likely present in natural environments were worked out. Instrumentation of ECOLOG (M.V. Gorlenko, P.A. Kozhevin, 2005) allows to determine not only the range of organic substrates used by microorganisms, but also to quantify the consumption of each substrate. For the processing and interpretation of a significant amount of information obtained in the course of the analysis of soil samples there are an apparatus of multidimensional mathematical statistics, cluster analysis, rank distribution, and ecological indexes of Shannon and Pielou. SUP method (multisubstrat test) possesses a high performance, good resolution (104), a satisfactory reproducibility and is a high-tech and effective tool to assess the physiological diversity. The article deals with the positive and negative aspects of the method. SUP reflects to some extent the potential of aerobic soil microorganisms using low molecular weight organic compounds in the catabolism. However, because of availability of several modifications, as well as some technical problem it is difficult to compare the results obtained by different authors, there is no unified SUP analysis protocol that is required for the comparative environmental studies and the establishment of relevant national and international databases. Thus, analysis of the carbon source utilization profiles (SUP) in BIOLOG system now is under development and testing, and with the accumulation of experimental data and critical analysis, it has good prospects in soil ecology, in research of the relationship between microorganisms and plants, and in assessment of the impact of anthropogenic factors. Source


Zhuchenko A.A.,Federal Agency of Scientific Organizations
Sel'skokhozyaistvennaya Biologiya | Year: 2015

For the first time in the world, A.A. Zhuchenko has carried a system analysis of the adaptive potential in cultivated plants, identified crucial features and qualitatively new mechanisms of adaptive responses of plants during ontogeny and phylogeny, substantiated and formulated the key concepts of plant genetics, ecological genetics of cultivated plants, ecological and genetic foundations of the adaptive system of plant breeding, adaptive crop production, and the strategy for adaptive intensification of agriculture. Source


Provorov N.A.,Federal Agency of Scientific Organizations
Sel'skokhozyaistvennaya Biologiya | Year: 2015

Legume-rhizobia symbiosis (LRS) is considered as a unique model of evolutionary biology, which allows us to study the trade-off between the adaptive and progressive evolution in biological systems formed by prokaryotes and eukaryotes. Macroevolution of LRS results is establishing the compartments for hosting microsymbionts that activate the development of N2-fixing nodules by special signals-lipo-chito-oligosaccharide Nod-factors. This evolution is dissected into a number of stages connected with the formation of: a) nodule endophytic associations (ancestral forms of rhizo-bia which retained the ability to fix CO2 and N2 in pure culture characteristic for their ancestors, occupy the intercellular spaces in nodules); b) primitive subcellular symbiosis (rhizobia which lost the ability to fix CO2 are located in infection threads penetrating into plant cells); c) intracellular mutualism (rhizobia, penetrated the plant cells to form the non-specialized symbiosomes where fix N2, maintaining the reproductive activity); d) symbiosis of altmistic type (rhizobia in specialized symbiosomes differentiate into bacteroids which irreversibly lost their reproductive activity providing a sharp increase in the N2-fixation intensity). This evolution occurs under the influence of natural selection induced in endosymbiotic populations, which can be individual (Darwinian, frequency-dependent) or group (inter-deme, kin) depending on the stmcture of microbial populations defined by mechanisms of host infection. Under the influence of this selection, complexity of the organization and the integrity of the LRS are increased, which serve as criteria for its evolutionary progress, as well as ecological efficiency of symbiosis (its impact on the partners' productivity). This interaction between bacteria and plants has been evolved from pleiotropic symbioses (dynamic equilibrium between mutualism and antagonism) to the mutual partners' exploitation (their equivalent exchange by products of N2 fixation and photosynthesis) and then to a highly-efficient mutualism of «altruistic» type (increased intensity of the symbiotrophic plant nutrition by nitrogen is the result of viability loss by bacteroids). Characteristics of macro-and micro evolution of symbiosis opens the broad prospects for the construction of highly efficient forms of LRS, including the creation of «altruistic» rhizobia strains (in which an increased symbiotic efficiency is combined with a reduced survival outside plant) as well as a combination of alternative development programs for effective symbiosis (expensive and economical) independently arisen in different groups of legumes. Source


Grishechkina S.D.,Federal Agency of Scientific Organizations
Sel'skokhozyaistvennaya Biologiya | Year: 2015

Various groups of agents are involved in biological crop protection to control pests and diseases. Of them, Bacillus genus possessing activity against harmful insects and phytopathogens is most promising and widely used. In this, the biologicals based on Bacillus thuringiensis (Bt) dominate. More than 70 varieties of Bt have been identified. These bacteria can survive for a long time after treatment. Preparations based on three Bt serovars (A, B, C) are mostly used for insects' biocontrol. Serovar A Bt subspecies can form crystal endotoxins which are active against Lepidoptera; serovar B Bt subspecies attack the larvae of mosquitoes and black flies, and phytophagous Diptera; and serovar C Bt subspecies are active against Coleoptera beetles. A new serovar F (fungi) of this bacillus was identified. Physiological and biochemical properties of Bacillus thuringiensis provide the assimilation of nutrient substrates and antibiosis against biocenosis partners. Batsikol, the biological preparation based on B. thuringiensis var. darmstadiensis (H10) with entomopathogenic action, was created at All-Russian Research Institute of Agricultural Microbiology (St. Petersburg). Batsikol contains components of culture liquid, spores, insecticidal and fungicidal exo- and endotoxins, due to which it possesses multifunctional properties. The article presents the mechanisms of entomopathogenic and antifungal action of microbial preparations based on Bt. Results of testing Batsikol effectiveness against various pests and diseases in field trials and vegetation experiments are shown. Liquid form of biological product was used in the study (spore titer of 3.5 1/2 109/ml). Field and vegetation tests were carried out in 1994-2013 in different regions of Russia (Leningrad, Novosibirsk, Volgograd region, North Ossetia, Stavropol and Primorsky regions). Batsikol was sprayed against phytophagous pests on vegetating plants. The efficacy against pests varied from 50 to 100 %. Different modes of application against phytopathogen were tested according to the type of parasitism and environmental characteristics of fungi (i.e., spraying, irrigation, seed treatment). In field experiments the efficacy of spraying strawberry plants against gray mold was 60-74 %. Soil watering was used against Fusarium wilt on tomatoes and flax with efficacy of 74-87 % and 34-42 %, respectively. When seeds were treated prior to sowing the efficacy was 66-71 % in case of soaking barley seeds against root rot, and 40-45 % while soaking potato tubers against damping-off. Based on the tests conducted with Batsikol in different regions of Russia, the spectrum of its activities against wide range of phytophagous pests and pathogenic fungi was revealed on different crops. The obtained data expand the understanding of Bt biology and, in particular, the action spectrum against various pests and diseases dangerous for many cultivated plants. Presented materials allow considering Bacillus thuringiensis as the basis of microbiological preparations with a multifunctional activity. The obtained data will allow expanding the scope of its application, and it will help to improve ecological situation. Source

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