INFLUENCE OF EXOMETABOLITES OF DIFFERENT VARIETIES OF CULTURAL PLANTS ON THE GROWTH AND DEVELOPMENT OF PATHOGENIC MICROMYCETES BIPOLARIS SOROKINIANA AND ALTERNARIA ALTERNATA

Objective. To establish the influence of exometabolites of winter wheat plants of Podolianka, Natalka, Skagen, Mulan varieties and oats of Skarb Ukrainy, Svitanok, Tembr varieties on the growth and development of Bipolaris sorokiniana micromycete, as well as the influence of onion of Tkachenkivska, Mavka, Veselka, Liubchyk, Variah, Harmonia varieties on the growth and development of the micromycete Alternaria alternata. Methods. Mycological, phytopathological, phytoimmunological. Results. Two hundred isolates of pathogenic micromycetes were isolated from the seeds of the studied crops of different varieties. The most common microbiota were: Bipolaris sorokiniana, Alternaria alternata, Alternaria tenuissima, Alternaria infectoria, Stemphylium vesicarium, Curvularia inaequalis. The highest incidence on wheat and oat seeds (over 80 %) was reported for B. sorokiniana, on onion seeds — for A. alternata. It was found that exometabolites of plants of different varieties can both inhibit and stimulate the rate of radial growth of mycelium of B. sorokiniana and A. alternata. It was proved that exometabolites of plants of wheat, oats, onion can significantly affect the reproductive capacity of the studied micromycetes, which reduced the number of spores per 1 cm2 of colony area almost 1.2–2.5 times compared to the control. This indicates that exometabolites of plants are characterized by fungicidal properties, which are due to a complex of biologically active substances that can inhibit the intensity of sporulation of B. sorokiniana and A. alternate. Conclusion. The antifungal property of root exometabolites of plants of the studied varieties significantly depends on the genotype of the variety. Therefore, an important timely task is to identify environmentally stable and flexible varieties that are characterized by group resistance to pathogens of fungal origin, as well as the search for mechanisms of action of fungicidal natural origin.

Soil health is the basis of organic agriculture

The biologization of agriculture is a topical issue both in Russia and in the world. The objective of the presented experiment was to confirm the positive effect biopreparations treatment of the fruit crops on the soil microbiota. As a result, in soil samples selected depend on the intensity of chemical fungicides application, from 1.15 x 104 to 1.23 x 104 CFU of micromycetes in one gram of absolutely dry soil were isolated. It was found that the largest amount of potentially pathogenic fungi was isolated in a soil sample cultivated using only chemical preparations - 20.5% of the total number of colonies. In the variant with the inclusion of biopreparation in the technology – from 7.2% to 11.0% of potentially pathogenic fungi of the total number of micromycetes. The most common among potentially pathogenic micromycetes were fungi of the genus Fusarium spp. Fungi of the genus Trichoderma were detected in all variants – not exceed 10% in the total number of micromycetes.

Biotechnology for production of recombinant hybrid proteins from plants and microbes with antifungal activity

The principle of obtaining recombinant antimicrobial polypeptides from plant and microbial origins as a part of chimeric proteins with thioredoxin by heterologous expression in a prokaryotic system is presented. The results obtained in terms of their antifungal activity in relation to plant pathogenic micromycetes allow us to consider these compounds as prototypes of some active substances of environmentally friendly biofungicides, as well as possible components of hybrid plant protection products against fungal diseases.

Pathogenic micromycetes of the Jumgal River basin by groups of economically useful plants

In the Jumgal River basin have been identified 223 species of phytopathogenic fungi and fungi-like organisms on 76 species of vascular plants from 125 genera. The distribution of phytopathogens in 8 economically useful plant groups was shown: forage, medicinal and alkaloid, honey, feeding, essential oil, dyeing, ornamental and weed plants.

Fungi ecological niches of the genus Fusarium Link.

Climatic variations and modern agricultural technologies change the fungi distribution area ofthe genus Fusarium Link., and lead to their dominance in pathocomplexes. The parasitic activity of fusarium fungi and localization of their ecological niches is determined by the activity of constantly expanding environmental and anthropogenic drivers. The fundamental niches of Fusarium pathogens are characterized by complexity and multidimensionality. Realized ecological niches change in space and time at the ontogenesis different stages of pathogenic micromycetes; the same species shows high heterogeneity in implementing its fundamental niche depending on environmental factors and the host plant species. The overlap level of ecological niches and interspecific relationships largely determine the species composition of the pathogenic complex of adiscrete phytocenosis.

Research on the content of pathogenic micromycetes and benz(a)pyrene in soils of urbanized territories of Perm Krai

The content of phytopathogenic fungi and the concentration of benz(a)pyrene in soil samples located near the oil refinery has been investigated. It has been found that in the vast majority of soil samples pathogenic micromicetes are represented by genera Fusarium, Rhizoctonia, Phytophthora, which have a negative effect on crops growth. The highest content of pathogenic micromycetes, amounting to10 CFU per 1 g of soil, was found in soil samples located directly on oil spill territory. It has been found that in an overwhelming number of soil samples, the concentration of benz (a) pyrene, which belongs to organic substances of grade I hazard, exceeds the MPC. The results of the study are consistent with earlier evidence that concentrations of pathogenic micromycetes and benz (a) pyrene are higher in anthropogenic-afected soils. This is due to the negative effect of oil hydrocarbons and benz (a) pyrene on useful soil microflora, and further settlement of the released ecological niche by pathogens. The company is given recommendations on the use of soil for cultivating technical crops or its exclusion from agricultural use.

Phytopathogenic micromycetes associated with conifers in Middle Siberia

Микроорганизмы, ассоциированные с растениями, в том числе хвойными, играют важную роль в их жизни, формируя микробные сообщества филлосферы, ризопланы и ризосферы. Условно состав таких комплексов можно разделить на патогенную и сапротрофную части. Знание видового разнообразия патогенов, вызывающих заболевания сеянцев и саженцев хвойных, крайне необходимо специалистам сферы лесовозобновления для коррекции агротехнических мероприятий и контроля качества посадочного материала. Цель данных исследований - изучение видового разнообразия патогенных микромицетов хвойных на территории Средней Сибири как в искусственных, так и естественных насаждениях. Применялись классические и современные методы идентификации патогенов. Приводятся данные по видовому составу патогенных микромицетов хвойных за последние 10 лет. Многолетние исследования видового разнообразия микромицетов хвойных на территории Средней Сибири выявили представителей 36 родов, относящихся к различным систематическим группам: Lophodermium Chevall., Lophodermella Höhn., Cyclaneusma DiCosmo, Peredo et Minte, Gremmenia Korf., Hypodermella Tubeuf, Lirula Darker, Sarea Fr., Herpotrichia Fucke, Gremmeniella M. Morelet, Coleosporium Lév., Chrysomyxa Unger, Melampsora Castagne, Melampsorella J. Schröt., Pucciniastrum G.H. Otth., Cronartium Fr., Typhula (Pers.) Fr., Mucor Fresen., Rhizosphaera L. Mangin et Har, Pestalotia De Not., Sclerophoma Höhn. (телеоморфа - Sydowia Bres.), Stagonospora (Sacc.) Sacc. (= Hendersonia Berk.), Lecanosticta Syd., Dothistroma Hulbary, Fusarium Link, Meria Vuill. (телеоморфа - Rhabdocline Syd.), Phoma Sacc., Didymella Sacc., Alternaria Nees, Cladosporium Link, Rhizoctonia DC., Botrytis P. Micheli ex Pers., Septorioides Quaedvl., Verkley et Crous, Epicoccum Link, Trichothecium Link., Verticillium Nees., Cylindrocarpon Wollenw. (телеоморфа - Neonectria Wollenw). Идентифицированные патогены вызывают преждевременную гибель ассимиляционного аппарата, нарушают деятельность корневой и проводящих систем, снижают качество семян хвойных растений. Microorganisms associated with plants, including conifers, play an important role in their life, forming microbial communities of the phyllosphere, rhizoplane, and rhizosphere. Conventionally, the composition of such complexes can be divided into pathogenic and saprotrophic parts. For specialists involved in reforestation, the knowledge of the species diversity of pathogens that cause diseases of seedlings of conifers is essential for correcting agrotechnical measures and controlling the quality of planting material. The goal of this research is to study the species diversity of pathogenic micromycetes of conifers in the Middle Siberia territory, both in artificial and natural plantings. Such long-term studies found representatives of 36 genera belonging to different taxonomic groups: Lophodermium Chevall., Lophodermella Höhn., Cyclaneusma DiCosmo, Peredo et Minte, Gremmenia Korf., Hypodermella Tubeuf, Lirula Darker, Sarea Fr., Herpotrichia Fucke , Gremmeniella M. Morelet, Coleosporium Lév., Chrysomyxa Unger, Melampsora Castagne, Melampsorella J. Schröt., Pucciniastrum G.H. Otth., Cronartium Fr., Typhula (Pers.) Fr., Mucor Fresen., Rhizosphaera L. Mangin et Har, Pestalotia De Not., Sclerophoma Höhn. (teleomorph - Sydowia Bres.), Stagonospora (Sacc.) Sacc. (= Hendersonia Berk.), Lecanosticta Syd., Dothistroma Hulbary, Meria Vuill.( teleomorph- Rhabdocline Syd.), Phoma Sacc., Didymella Sacc., Alternaria Nees, Cladosporium Link, Rhizoctonia DC., Botrytis P. Micheli ex Pers., Septorioides Quaedvl., Verkley et Crous, Epicoccum Link, Trichothecium Link., Cylindrocarpon Wollenw. (teleomorph - Neonectria Wollenw). The identified pathogens cause premature death of the assimilation apparatus, disrupt the activity of the root and vascular systems, and reduce the quality of coniferous plants seeds.

FUNGAL DISEASES OF ASPARAGUS VIGNA IN THE SOUTH OF WESTERN SIBERIA

Increasing popularity of asparagus bean (Vigna unguiculata (L.) Walp.) − a new for Russia vegetable crop requires comprehensive study including resistance to biotic environmental factors. Composition of pathogens of germinating seeds, plants (roots, leaves, stems, fruits) of large collection of asparagus bean from the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) and the Bioresource Scientific Collection of the CSBG SB RAS UNU No. USU 440534 have been investigated. Plants of 87 samples of asparagus bean were grown in the unheated plastic film greenhouse on the south of Western Siberia (54 ° N lat. 83 ° E) and examined for infestations of diseases in the Central Siberian Botanical Garden and Novosibirsk State Agrarian University (Novosibirsk). The infection of seeds with pathogenic micromycetes was determined according to GOST 12044-93 (similar to common beans) using the methods of mycological analysis and the Petri-dish moist chambers, also on Chapek media and KDA media. The main pathogenic micromycetes are: on germinating seeds − species of the genera Fusarium, Aspergillus, Penicillium, Alternaria, Mucor, Botrytis cinerea, Sclerotinia sclerotiorum; on seedlings − Fusarium solani; during fruiting on fruits and stems − B. cinerea and S. sclerotiorum; on the root collar − S. sclerotiorum. The dominant forms of white mold were stem, root collar, fruits. Five samples that showed a high level of resistance to B.cinerea and S.sclerotiorum have been selected. System for asparagus bean disease surveillance which should be built in the calendar-phenological sequence, has been recommended.