scholarly journals Antagonism of Bacillus thuringiensis to phytopathogenic micromicetes as pathogens of apple trees

Author(s):  
О. Sherstoboeva ◽  
А. Krzyhanivsky ◽  
А. Bunas

Antagonistic microorganisms, producing bactericidal and fungicidal substances, spread in space and occupy various ecological niches. Antagonistic action of microorganisms can be combined with a number of other properties that can be used by humans for their own purposes. Microorganisms — agents of biological products often have a multifunctional effect on the components of the agroecosystem, which under the influence of various environmental factors could have positive and negative consequences. The aim of the study was to study the effect of new highly active entomopathogenic strains of Bacillus thuringiensis on non-target objects — components of the biocenosis of the apple orchard. When developing technologies for biocontrol of the number of apple trees pests using B. thuringiensis revealed an additional positive protective effect — reducing the number of pathogens of fungal diseases on the leaf surface. Treatment of apple leaves with a liquid culture of strain B. thuringiensis 0376 after 72 hours of application reduced the number of scab of Fusicladium dendriticum by 7 times, and the pathogen of monolisis of Monilia fructigena — 9 times. Strain B. thuringiensis 0371 showed the highest level of antagonism, because in vitro completely inhibited the growth and development of micromycetes on the surface of the nutrient medium. On the leaf surface, the application of culture strain 0371 reduced the number of Fusicladium dendriticum by 92%, and Monilia fructigena — by 86% after 72 hours of treatment. In a field experiment when treating apple trees with a culture of this strain, scab development decreased by 7.1%. Strain B. thuringiensis 787 did not show antagonism against phytopathogenicmicromycetes during co-cultivation on nutrient medium, which may be explained by its inability to produce water-soluble exotoxin, in contrast to strains of B. thuringiensis, which are antagonists of scab and apple monolisis. Strain B. thuringiensis 0371 requires further research and development of its formulations, because it is promising for the creation of a complex biological product with insect-fungicidal properties for use in ecological and agriculture friendly technologies.

1959 ◽  
Vol 5 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Ellicott McConnell ◽  
A. Glenn Richards

Bacillus thuringiensis Berliner produces in vitro a heat-stable, dialyzable substance which is toxic for insects when injected. The same or a similar substance is produced in vivo. The toxic principle is of unknown composition. It is heat-stable, water-soluble, dialyzable, and resistant to low temperatures. It is probably neither a protein nor a lipid. Clearly it is distinct from the heat-labile inclusion bodies and from lecithinase. Growth-curve studies showed that the heat-stable toxin appeared in liver broth cultures during the active growth phase, prior to the formation of spores or inclusion bodies. An attempt to produce the toxic principle from culture media in the absence of bacteria was unsuccessful from sterile inocula both from in vivo and in vitro sources. The LD50 for larvae of Galleria mellonella injected with autoclaved supernatant from a 10-day-old liver broth culture of B. thuringiensis was determined to be 0.00036 ml per larva or 0.002 ml per gram of larvae. Approximately the same level of toxicity was found for another caterpillar, a fly larva, and cockroaches. After larvae of Galleria or Pyrausla have been dead for more than 2 days from infection with B. thuringiensis the bacillus could no longer be recovered. A sublethal amount of the heat-stable toxin injected into old larvae of Galleria delayed emergence of the adults by 30 to 40%. The non-pathogenic Bacillus cereus was found to produce a similar-acting, heat-stable toxin under the same conditions that one is produced by B. thuringiensis.


2021 ◽  
Vol 37 ◽  
pp. 00033
Author(s):  
L Levshakov ◽  
N Volobueva

The value of foliar dressing is presented to achieve the maximum productivity of cultivated crops in agropedocenoses of the forest-steppe zone of the Russian Federation. When cultivating apple orchards in perennial agropedocenoses according to intensive technologies, the optimization of the nutritional regime is one of the most significant factors in obtaining a stably high crop yield of high-quality fruits. To fully provide apple trees with nutrient elements and growth biostimulators during the growing season, it is necessary to use special fat and water-soluble fertilizers and growth biostimulators. Most effectively, they are applied along the leaf surface as a foliar dressing. The leaf surface systems we developed and tested include the introduction of macro-, meso- and microelements and biological stimulating agents. The latter include various groups and types of amino acids, root, growth and development, flowering and setting, ripening and staining stimulating agents. The use of an integrated foliar dressing system has made it possible to provide the most complete need for apple trees with the necessary nutrients and compounds during the entire growing season. The obtained experimental data showed a high efficiency in changing a balanced system of foliar dressing in an intensive apple orchard. Compared to the control, there was a significant increase in the growth activity of the central conductor and fruit wood. Fruit setting rates, caliber and weight of apples and therefore more than 95% of the yield corresponded to the highest and first grade. The yield increased significantly compared to the control, it was from 28 to 66% for varieties and variants. Experimental studies showed high efficiency of foliar dressing with special fertilizers and growth biostimulating agents.


2021 ◽  
Vol 36 ◽  
pp. 05008
Author(s):  
O.O. Novikov ◽  
M.S. Romanova ◽  
N.I. Leonov ◽  
E.I. Kosinova

In the work, the study of six different nutrient medium compositions’ influence on the growth and development of a healthy Solnechny potato variety in the growing process in laboratory conditions in vitro was carried out. The influence of different nutrient medium compositions on plant height, number of leaves/internodes, plant weight and total leaf surface area was studied. It was revealed that nutrient media with BAP addition cause a decrease in all of the above indicators. In addition, nutrient media with this growth regulator lead to the appearance of microtubers on the plants. It has been shown that the inclusion of GA and IAA growth regulators in nutrient media leads to a slight increase in the number of internodes. An increase in the total leaf surface area was noted in the above options. It should be noted that the nutrient medium options with the addition of GA and IAA led to a decrease in the mass and length of the root system of Solnechnyi variety potato plants.


Author(s):  
E. V. Lobodina ◽  
I. I. Suprun ◽  
A. O. Avakimyan ◽  
E. A. Al-Nakib

The work reflects the aspects of introducing two varieties of apple trees into the culture in vitro: Prikubanskoe and Kubanskoe Bagryanoe. The aims of study included testing a new disinfection protocol that accurately regulates the content of active chlorine in the disinfecting solution, as well as studying the regenerative ability of explants of apple trees of the Prikubanskoe and Kubanskoe Bagryanoe varieties on different culture medium: Murashige and Skoog (MS) ¼ NH4 NO3 , and Kvorin-Lepuavra (QL). The disinfection protocol used made it possible to obtain an insignificant level of explant contamination with fungal infection in passage zero, which indicates the effectiveness of the tested extraction protocol. The contamination of explants in passage zero by fungal infection was insignificant, which indicates the high efficiency of the sterilizing agent. The level of bacterial infection is higher in the Kubanskoe Bagryanoe variety (21.3 % of the total amount of explants). The influence of the component composition of nutrient media on the primary growth of apple micro-shoots was revealed. The following results were obtained: the yield of viable explants of the Prikubanskoe variety grown on nutrient medium MS ¼ NH4 NO3 was 44,4 %, which is 16,4 % higher than explants grown on QL medium (28 %). Explants of the Kuba nskoe bagryanoe variety, in turn, have a yield of vital microplants grown on MS ¼ NH4 NO3 16.7 %, which is 30.4 % lower than explants grown on QL medium (47.1 %). The combined effect of the genotype and the composition of the nutrient medium on the development of explants was statistically significant for the studied parameters. The share of the cumulative effect of factors of the variety x medium is 74.93 %, the influence of the genotype is 20.72 %. The data obtained indicate the variety specificity of the nutrient medium during clonal micropropagation of these apple varieties.


1946 ◽  
Vol 84 (6) ◽  
pp. 607-621 ◽  
Author(s):  
Christian B. Anfinsen ◽  
Quentin M. Geiman ◽  
Ralph W. McKee ◽  
Richard A. Ormsbee ◽  
Eric G. Ball

1. Methods have been described for the preparation and sterilization of a synthetic nutrient medium which supports normal growth during one 24 hour asexual cycle of the erythrocytic form of P. knowlesi. 2. Successive subcultures with good multiplication can be carried out when whole blood or plasma is added to the medium. Data are presented from two such experiments where the sixth and seventh generations, respectively, were injected into normal monkeys. In both cases, the injections produced clinical malaria and in one, an abnormally severe course was observed. 3. A high percentage (95 per cent) of O2 inhibits multiplication in in vitro cultures. A gas phase approximating alveolar air permits normal development. A lower percentage (0.37 per cent) of O2 in the gas phase supports growth at least as well. 4. Certain experiments indicate that in vitro growth is better supported in normal monkey plasma than in plasma from parasitized monkeys. Heating of parasitized plasma to 56°C. for 30 minutes removed the deleterious effect. 5. A nutritional need by the parasite for glucose and p-aminobenzoic acid has been shown. Attempts to demonstrate the need for other individual components of the nutrient medium have not been successful though the effect of the absence of blocks of nutrient such as purines and pyrimidines, amino acids, or water-soluble vitamins can be observed. 6. Further assay of the nutritional requirements of the parasite appears to be hampered by the supply of nutrient furnished by the red cells and plasma. Cultivation of parasitized cells washed free of plasma and resuspended in synthetic medium containing 1 per cent serum albumin has been accomplished as one step directed toward the removal of such interfering factors.


2016 ◽  
Vol 23 ◽  
pp. 49-53
Author(s):  
O. V. Sherstoboieva ◽  
O. A. Demidov ◽  
A. B. Kryzhanivskyi

It was established that treatment of apple trees for control over harmful insects with liquid preparations based on entomopathogenic strains of Bacillus thuringiensis 03071, 0376, and 0408 which synthesize protein endotoxins and water-soluble exotoxin, provides a yield of fruit according to the level of 16.2–18.1 t/ha, whereas treatment with preparation based on strain B. thuringiensis 787, that does not contain exotoxin in metabolites, contributes to the yield at the level of only 12.7 t/ha. Treatment of apple trees with preparation based on the strain B. thuringiensis 0408 contributed to growth of fruits with increased vitamin C concentration. Biopreparations had no negative impact on the quality of resulting product, in particular on the content of sugars and organic acids in apple fruits. Only after treatment of apple trees with preparation based on the strain B. thuringiensis 0371 and chemical insecticide Confidor extra, slight exceed of optimal sugar-acid balance in apple fruits was found for studied variety Jonagold by 1.1 and 1.5 U, respectively.


Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size ‘1’. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website


Author(s):  
Lê Thanh Long ◽  
Nguyễn Văn Toản ◽  
Nguyễn Văn Huế ◽  
Trang Sĩ Trung ◽  
Vũ Ngọc Bội

Chủng D1 phân lập từ các mẫu chuối có vết bệnh thán thư điển hình được sử dụng để nghiên cứu khả năng kháng nấm của chitosan hoà tan trong nước (Water-soluble chitosan_WSC) ở điều kiện in vitro. Kết quả phân tích trình tự gen mã hoá 28S rRNA của chủng D1 cho thấy tương đồng trình tự cao với các trình tự tương ứng của loài Colletotrichum musae và được ký hiệu là Colletotrichum musae D1. Kết quả các thí nghiệm đều cho thấy C. musae D1 rất nhạy cảm với WSC, hiệu lực ức chế tăng khi tăng nồng độ WSC xử lý ở điều kiện in vitro. Trên môi trường PDA, nồng độ 1,6% WSC ức chế hoàn toàn sự sinh trưởng của sợi nấm C. musae D1, nồng độ ức chế 50% (PIRG50) và nồng độ ức chế tối thiểu 90% (MIC90) tương ứng với nồng độ WSC 0,28% và 0,88%. Trong môi trường PDB, giá trị IC50 và MIC90 tương ứng là 0,11% và 0,43% và sự phát triển của sợi nấm C. musae D1 bị ức chế hoàn toàn ở nồng độ 0,8%. WSC không chỉ ức chế sự nảy mầm mà còn gây biến đổi bất thường bào tử nấm khi quan sát trên kính hiển vi.


2020 ◽  
Vol 62 ◽  
pp. 85-90
Author(s):  
L. V. Tashmatova ◽  
O. V. Matsneva ◽  
T. M. Khromova ◽  
V. V. Shakhov

The article presents methods of experimental polyploidy of fruit, berry and ornamental plants. The purpose of this review is to highlight the problems and prospects of polyploidization of plants in the open ground and in vitro culture and the possibility of their application for apple trees. For the purpose of obtaining apple tetraploids as donors of diploid gametes, seed seedlings were treated with a solution of colchicine in concentrations of 0.1-0.4 % for 24 and 48 hours. Colchicine concentrations of 0.3 % and 0.4 % at 48 hours of treatment had a detrimental eff ect on their development. As a result, tetraploids and chimeras were obtained from seeds from free pollination of the varieties Orlik, Svezhest, Kandil Orlovsky, as well as from seeds obtained from crossing the varieties Svezhest×Bolotovskoe, Moskovskoe Оzherel’e×Imrus, Girlyanda×Venyaminovskoe. The optimal concentration of colchicine was 0.1 %. Methods of colchicine treatment have been studied: 1) adding to the nutrient medium, colchicine concentration: 0.01%, 0.02%, exposure time 24h-19 days; 2) applying amitotic solution to the growth point, colchicine concentration: 0.1 %, 0.2 %, exposure time 24h-7 days. To increase the penetration of colchicine through the cell walls, a 0.1 % dimexide solution was used. Studies have shown that high concentrations and prolonged exposure to colchicine reduce the viability of explants.


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