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0INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE "STATUS AND DEVELOPMENT PROSPECTS OF FUNDAMENTAL AND APPLIED MICROBIOLOGY: THE VIEWPOINT OF YOUNG SCIENTISTS" _25-26 SEPTEMBER, 2024_
STUDY OF THE ACTIVE ANTAGONISTIC PROPERTIES OF BACTERIAL STRAINS BELONGING TO THE BACILLUS
GENUS
1Rajabova Dinora Shuxrat qizi, 2Roxatalieva Husnida Bahodirjon qizi, 3Azimova Nodira Shoyim qizi, 4Karimov Husniddin Xolmamatovich
1Master of the National University of Uzbekistan named after Mirzo Ulugbek, 2Master of the National University of Uzbekistan named after Mirzo Ulugbek, 3Senior researcher of the
Institute of Microbiology, 4Head of the laboratory of the Institute of Microbiology https://doi.org/10.5281/zenodo.13829165
Abstract. In this research, the antagonistic properties of bacterial strains belonging to the genus Bacillus, which are strong antagonists against fungal isolates of F. solani 915, A. flaus 1/15, V. dahliae 936, S. chartarum 9/17, which are considered to be strong pathogens that cause diseases in plants, were studied.
Key words: B. subtilis, B. paramycoides, antagonism, phytopathogen, A. flavus, F. solani.
Nowadays, healthy, sustainable and inclusive food systems across countries are critical to achieving global development goals. The development of green agriculture is two to four times effective in increasing the income of the population compared to other industries. In this regard, increasing productivity by reducing and preventing phytopathogenic diseases is considered one of the urgent tasks. To date, the spread of pathogenic fungi, which cause various diseases, especially in fruit plants, is observed in the northeastern part of our Republic [4].
Many strains belonging to the genus Bacillus have been recognized as biocontrol agents due to their direct action against phytopathogenic microorganisms and stimulation ofplant growth [1].
For example, Bacillus thuringiensis bacterium Pythium ultimum and Fusarium oxysporum f. sp. lycopersici species have been found to reduce or stop their growth and lyse their mycelia [5]. In some countries, B. subtilis is used against corn fusarium wilt, wheat, oat, barley rhizoctonia, carrot root rot, cotton sprout rhizoctonia, clove fusarium, and apple canker caused by Nectria galligena. Positive results were also obtained in the tests [7]. Recently, as a result of research conducted by scientists, the antagonist B. subtilis-V-40 strain against Verticillium dahliae, Fusarium graminaearum, Sclerotinia sclerotiorum, Phytophthora infestans and other fungi was selected using selection [2].
The purpose of this study is to identify active antagonistic strains against pathogenic fungi in various agricultural crops.
Bacterial strains belonging to the genus Bacillus, isolated within the framework of practical project No. IL-402104392, implemented in the Molecular Biology Laboratory of the Institute of Microbiology of the Academy of Sciences of the Republic of Uzbekistan Microbiology Institute, were used in the research.
Antagonistic bacterial strains selected as objects for the experiment - B. subtilis 6/23, B. subtilis 6/20 isolated from sweet pepper (Capsicum annuum) leaves; B. pumilus 2/17 isolated from tomato stem; B. pumilus 4/24, B. pumilus 1/2 isolated from potato leaves; B. subtilis 1/17, B. subtilis 1/16, B. paramycoides 1/15 strains were cultivated in MPA medium for 48 hours at a temperature of 30-32°C in a thermostat. As phytopathogenic fungi, F. solani 915, A. alternata 879, V. dahliae 936 fungal strains were used from the collection of the Institute of Genetics and
INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE "STATUS AND DEVELOPMENT PROSPECTS OF FUNDAMENTAL AND APPLIED MICROBIOLOGY: THE VIEWPOINT OF YOUNG SCIENTISTS" _25-26 SEPTEMBER, 2024_
Experimental Plant Biology of the Federal Republic of Uzbekistan, and A. flaus 1/15 were isolated within the framework of the practical project No. IL-402104392 at the Institute of Microbiology.
The experiment was conducted on the basis of the dual culture plate method, as "two antagonists - one pathogen" on the surface of the plate to determine the antagonism against pathogenic fungi [3]. 0.1 ml suspensions of bacterial strains cultivated in GPB (meat peptone broth) medium with a concentration of 109 KHB/ml were poured into Petri dishes with MPA (meat peptone agar) medium and cultivated as a form of a lawn. Blocks with a diameter of 6 mm were cut from antagonistic Bacillus bacteria cultivated in agar nutrient medium in Petri dishes, and 2 blocks were placed on the samples cultivated with 0.1 ml suspension of fungal isolates in Chapek agar nutrient medium in a lawn method [6].
Experiments were conducted in 3 replicates. All samples were incubated at 30-32°C for 35 days. Antagonism rings were measured using HiAntibiotic ZoneScale-c (Himedia).
Table 1.
Antagonism of the test strains against phytopathogenic A. flaus 1/15, A. alternata 879 and
F. solani 915 micromycetes (mm)
Strain names A. flaus 1/15 A.alternata 879 F. solani 915 V. dahliae 936
B. Subtilis 1/16 39±0,9 37±0,5 39 0
B. Subtilis 1/17 0 40±0,6 0 23
B. Subtilis 6/20 0 18±0,2 0 11
B. Subtilis 6/23 0 16±0,1 14 0
B. Paramycoides 1/15 14 20±0,9 0 40
B. Pumilus 1/2 20±0,9 17±0,8 0 0
B. Pumilus 2/17 0 0 0 0
B. Pumilus 4/24 13 16±0,8 0 11
__Table 2.
Bacteria strains: Fungus micromycete:
B. subtilis 1/16; Antagonism of bacterial strains against the fungal micromycete A.
B. subtilis 6/23 flaus 1/15:
INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE "STATUS AND DEVELOPMENT PROSPECTS OF FUNDAMENTAL AND APPLIED MICROBIOLOGY: THE VIEWPOINT OF YOUNG SCIENTISTS" 25-26 SEPTEMBER, 2024
B. subtilis 1/16; subtilis 6/23
B.
B. subtilis 1/16 B. subtilis 6/23
B.paramycoides 1/15 B. subtilis 1/17
Antagonism of bacterial strains against the fungal micromycete A.alternata 879:
Antagonism of bacterial strains against the fungal micromycete F. solani 915:
Antagonism of bacterial strains against the fungal micromycete V. dahliae 936:
B. pumilus 1/2 20mm, B.sSubtilis 1/16 39mm from strains of bacteria antagonistic to the phytopathogenic A. flaus 1/15 fungus selected for the experiment; B. subtilis 1/16 37mm, B. subtilis 1/17 40mm, B. paramycoides 1/15 20mm against A. alternata 879; B. subtilis 1/16 39mm represented the most active antagonism against F. solani 915. B. subtilis 1/17 23 mm, B. paramycoides 1/15 bacterial strain 40 mm zone against V. dahliae 936 fungal micromycete. Researches on the morphology of representatives of the genus Bacillus, which produce active antagonistic phytohormone, are being continued.
Based on the results of the research, it can be concluded as follows that Bacillus subtilis and Bacillus paramycoides bacterial genera represent widely influential antagonism to Fusarium, Alternaria alternara, Aspergillus flavus isolates, which are highly pathogenic to plants.
INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE "STATUS AND DEVELOPMENT PROSPECTS OF FUNDAMENTAL AND APPLIED MICROBIOLOGY: THE VIEWPOINT OF YOUNG SCIENTISTS" _25-26 SEPTEMBER, 2024_
In addition, these strains with active antagonistic properties can be used in biological control against phytopathogens.
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2. A.SH.XAMRAYEV, B.A.XASANOV, B.A.SULAYMONOV, AG.KOJEVNIKOVA O'SIMLIKLARNI BIOLOGIK HIMOYA QILISH VOSITALARI
3. Clara Pliego; Cayo Ramos; Antonio de Vicente; Francisco M. Cazorla. Screening for candidate bacterial biocontrol agents against soilborne fungal plant pathogens. doi:10.1007/s11104-010-0615-8. 2011.- 340(1-2), 505-520.
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5. G. A. Amer, Rashmi Aggarwal, D. V. Singh and K. D. Srivastava „Interaction of Bacillus thuringiensis with Pythium ultimum and Fusarium oxysporum f. sp. lycopersici: Possible role in biological control'' Vol. 73, No. 3 pp. Published By: Current Science Association 10 August 1997. 284-286 (3 pages)
6. Hélène Cawoy, Delphine Debois, Laurent Franzil, Edwin De Pauw, Philippe Thonart and Marc Ongena Lipopeptides as main ingredients for inhibition of fungal phytopathogens by Bacillus subtilis/ amyloliquefaciens. 2014.
7. Sheraliyev A.Sh., Umumiy va qishloq xo'jalik fitopatologiyasi, (Darslik). Talqin" nashryoti. Toshkent, 2004
