Biotechnology

Biological products for plant protection: types and methods of application
05.10.2021
Fertilizer for orchids
Fertilizer for orchids
06.10.2021

Biotechnology development

Biotechnology (Βιοτεχνολογία, from the Greek. Bios – life, techne – art, skill and logos – word, teaching) – the use of living organisms and biological processes in production. Biotechnology is an interdisciplinary field that emerged at the intersection of biological, chemical, and technical sciences. The development of biotechnology is associated with the solution of the global problems of mankind – the elimination of shortages of food, energy, mineral resources, improvement of the state of health care and the quality of the environment.

History of biotechnology

Since ancient times, people have used biotechnological processes in baking, preparing fermented milk products, winemaking, etc., but only thanks to the works of Louis Pasteur in the middle of the 19th century, the connection between fermentation processes and the activity of microorganisms was proved, traditional biotechnology received a scientific basis.

In the 40-50s of the 20th century, when the biosynthesis of penicillin by fermentation methods was carried out, the era of antibiotics began, which gave impetus to the development of microbiological synthesis and the creation of a microbiological industry.

In the 60-70s of the XX century, cell engineering began to develop rapidly.

With the creation of the first hybrid DNA molecule “in vitro” in 1972 by P. Berg’s group in the USA, the birth of genetic engineering was formally connected, which opened the way for a conscious change in the genetic structure of organisms so that these organisms could make the products necessary for a person and carry out the necessary processes. These two areas have shaped the new biotechnology, which has little in common with the primitive biotechnology that humans have used for millennia. It is significant that in the 1970s the term “biotechnology” itself became widespread. Since that time, biotechnology has been inextricably linked with molecular and cellular biology, molecular genetics, biochemistry, and bioorganic chemistry. For a short period of its development (25-30 years), modern biotechnology not only achieved significant success but also showed unlimited possibilities for using organisms and biological processes in various industries and the national economy.

Biotechnology as a science

Biotechnology is a set of fundamental and applied sciences, technical means aimed at obtaining and using cells of microorganisms, animals, and plants, as well as their metabolic products: enzymes, amino acids, vitamins, antibiotics, etc.

A technology that combines natural and engineering sciences with the aim of using organisms, cells, their parts, or their molecular counterparts to produce specific chemicals and materials.

Biotechnology, which encompasses industrial microbiology, is based on the use of knowledge and methods of biochemistry, microbiology, genetics, and chemical technology, makes it possible to benefit in technological processes from the properties of microorganisms and cell cultures. Modern biotechnological processes are based on recombinant DNA methods, as well as on the use of immobilized enzymes, cells, and cellular organelles.

Main directions of research

Development of scientific foundations for the creation of new biotechnologies using methods of molecular biology, genetic and cellular engineering.

Obtaining and using biomass of microorganisms and products of microbiological synthesis.

Study of the physicochemical and biochemical foundations of biotechnological processes.

Using viruses to create new biotechnologies.

Biological methods of protection

The biological method consists in using their natural enemies (predators, parasites, herbifagives, antagonists), their waste products (antibiotics, pheromones, juveniles, biologically active substances), and entomopathogenic microorganisms to reduce their number and harmfulness to protect plants from harmful organisms, as well as the creation of favorable conditions for the activity of useful species in agrobiocenoses, that is, the use of “living against living”.

A positive factor in the application of the biological method is its environmental friendliness. Biological agents can be used without limiting the frequency of application, while the number of treatments for plants with chemical pesticides is strictly regulated.

Biological plant protection is based on a systematic approach and integrated implementation of two main directions: preservation and promotion of the activity of natural populations of useful species (entomophagous, microorganisms), self-protection of cultivated plants in agrobiocenoses, and renewal of agrobiocenoses with useful species, which are lacking or which are absent. The fundamental difference between the biological method of plant protection from any other is the use of the first direction, which is carried out, using biological preparations, by methods of seasonal colonization, introduction, and acclimatization of zoophagous and microorganisms. Agrobiotechnical measures and some methods of processing, with the help of which it is possible to create favorable conditions for the vital activity of zoophagous, contribute to the reproduction and efficiency of the activity of useful species.

The cultivation of pest-resistant crop varieties contributes to the formation of more viable pest populations.

Each of the main means of the biological method (the use of zoophagous, useful in plant protection of microorganisms) has its own characteristics and is effective inappropriate conditions. These funds do not eliminate but complement each other. Nowadays, special attention is paid to the search for ways of joint application of biological protection with other methods in integrated systems of plant protection against harmful organisms. The main objective of this method is to study the conditions that determine the effectiveness of natural enemies of pests and to develop ways to regulate their number and relationships with populations of pests.

Entomophagy

The natural enemies of insects include entomophagous (predators and parasites) and pathogenic (entomopathogenic) microorganisms. The latter include pathogens of viral, bacterial, fungal, protozoal, and nematode (parasitic roundworm species) diseases. Numerous entomophagous are found among insects, spiders, and ticks. Vertebrates – insectivorous birds, fish, reptiles, and mammals – have a significant benefit in the destruction of pests. A number of Coleoptera are also effective predators, many species of which, used to protect plants from pests, belong to the Coccinellidae family or ladybirds, which feed on aphids, leaf rollers, whiteflies, and phytophagous mites.

Entomophagy lives in different environmental conditions and therefore differ in a different way of life. Predators lay eggs in pest colonies or in the environment that surrounds them. Some feed only in the larval phase (syrphid flies, gall midges, goldfish common), or in the adult phase (scorpionflies, ants, many wasp species), others in the adult and larval phase (thrips, bugs, most Lepidoptera, coccinellids, ground beetles, flies, etc.).

There are many predators among bedbugs (macrolophus, podiums). Most of the available predators among ticks belong to the order of parasite forms and acariforms. The main ways of using entomophagous and macrophages against pests are seasonal colonization, introduction, and acclimatization, intra-area migration, creation of conditions for their reproduction.

Seasonal colonization

Seasonal colonization involves artificial mass breeding and the release of entomophagous into the required habitat. In populations, entomophagous are often few and far between, and they cannot control the reproduction of pests on their own. The mass release of insects is carried out at the beginning of the phase, when the pests are better damaged by entomophagous, subsequently, they will reproduce on their own.

The method of seasonal colonization involves the use of species of the genus Trichogramma, which are used against gnawing, leaf-gnawing scoops, whiteflies, moths, leaf rollers, etc., as well as parasites of the greenhouse whitefly enkarsia, dragon – a parasite of the cotton worm, stem butterfly, parasite of the American white butterfly, etc. like that. Predators are also used – cryptolemus against worms, phytoseiulus against spider mites, aphidimiza predatory galitsa to destroy aphids in the protected ground, and the like.

Introduction and acclimatization are applied against quarantine pests, which have a limited distribution in the country.

Natural enemies restrain the reproduction of the pest in its homeland, and they are absent in the new geographical area. Effective zoophagous and microorganisms for delivery and acclimatization are found in the homeland of the pest and relocated to new areas. The best results are obtained with the introduction of highly specialized species that are adapted to subsistence due to one pest, disease, and weeds. Intraoral relocation consists of the relocation of effective, more often specialized, natural enemies from old foci, where the number of pests is decreasing, to new parts of the range, where these enemies are absent or have not yet accumulated.

Microorganisms that damage harmful species are used for plant protection in the form of biological preparations. Most biological bacterial preparations are created on the basis of crystal-forming bacteria of the Bacillus thuringiensis Berl. Group, which creates spores and crystals that can dissolve in the intestines of insects, where they enter with food.

Fungal preparations contain spores of entomopathogenic fungi belonging to the imperfect ones.

Viral biological preparations are made on the basis of polyhedrosis and granulosa viruses, which most often infect Lepidoptera.

Biologically active substances

In living systems at all levels of the organization, a common way of transferring data is chemical interaction. Recently, much attention has been paid to the development and use of biologically active substances that ensure the relationship between living organisms in biocenoses, their growth, and development.

Pheromones

The main group of biologically active substances is pheromones. Pheromones are chemicals that insects produce and release into the environment. These substances elicit appropriate behavioral or physiological responses. There are various groups of pheromones – sex, aggregation, trace, and the like.

Sex pheromones, which are most often secreted by females to attract males, have become most widespread in plant protection practice. The most studied are the pheromones of Lepidoptera, Coleoptera, bedbugs, Retinoptera, and Termites. Based on the determination of the structure of natural insect pheromones, their synthetic analogs have been created. Sex pheromones are used to detect and determine the area of ​​distribution of pests, to signal the timing of the application of protective measures, to determine the density of pest populations, as well as to protect crops by mass trapping of males (“male vacuum”) and disorientation, attracting males during chemical sterilization.

The method for disorienting insects involves saturating the area with high concentrations of synthetic pheromone and disrupting pheromone communication between males and females. As a result, unpaired females lay unfertilized eggs, which leads to a decrease in the number of the species.

Hormones

It was found that the processes of metamorphosis, molting, reproduction and diapause of insects are regulated by hormones. The most studied are juvenile (larval), ecdysone (larval) and brain hormones.

Hormones were synthesized and obtained as chemical compounds that differ in structure from natural ones, but imitate their biological activity – they act as regulators of the growth and development of insects. In plant protection, chitin synthesis inhibitors and juvenoids have been acquired for practical use. Hormonal drugs work significantly differently from traditional insecticides. They are not poisonous, but they cause disturbances in embryonic development, metamorphosis, and sterilization. Chitin inhibitors interfere with cuticle formation during molting. Juvenoids cause death during the completion of larval or look development and are inhibitors of chitin synthesis during the next molt.

The biological method of combating plant diseases is to use the phenomena of over parasitism, antibiosis, existing in nature, that is, antagonistic relationships between organisms that develop on plants and in the soil.

Antibiotics

Now, in the XXI century, most attention is paid to the study and use of antagonists and their metabolic products – antibiotics. As antagonists, many phytopathogens are well studied and used, for example, for fungi of the genus Trichoderma. They are widespread in soils of various types and produce antibiotics – gliotoxin, viridin, trichodermin, sotsucacillin, alamecin, etc., have antibacterial and antifungal properties. On the basis of these pathogens, the drug Trichodermin was created.

An important role in the biological protection of plants from diseases is assigned to microfluidic fungi – supraparasites (genus Ampelomyces, Trichothecium). The imperfect mushroom Trichothecium Roseum Lin forms the antibiotic trichothecenes, which inhibits the development and growth of many fungi – pathogens of cucumber powdery mildew, moniliasis, and the like. On its basis, the biological preparation trichothecenes were created.

Weed control

The biological method of weed control was first applied against the lanthanum shrub in Hawaii, the Orthezia insignis Pung. In Ukraine, biological protection is used against the parasitic chlorophyll-free plants of the top, affecting more than 120 species of cultivated plants, and more sunflowers. Among the organisms that reduce the number of the spinning top, the photolysis fly is effective. Nowadays, the fight against ragweed, which spreads in Ukraine on arable lands, pastures, meadows, roadsides, is gaining great importance. Since 1978, the ragweed beetle introduced from North America has been used against it.

Genetic method

The genetic method of combating harmful organisms was developed and proposed by A.S. Serebrovsky (1938, 1950). This method assumes saturation of the natural population of the pest with genetically defective individuals of the same species. Females of the natural population, mating with such individuals, lay nonviable eggs, do not give offspring, the pest self-destructs. The genetic method is carried out by radiation and chemical sterilization. Radiation sterilization provides for the mass breeding of pests, their irradiation (gamma rays, X-rays) and the next release into fruit plantations, crops. In irradiated individuals, damage to the chromosomal apparatus occurs. In the case of chemical sterilization, chemical substances with alkylating compounds, antimetabolites and antibiotics are used as sterilizers. The former cause sexual sterility in females and males, antimetabolites cause sterility in females.

The genetic control method was applied in 1954 against the gray fly fly on the island of Curacao, which causes significant damage to animal husbandry. The release of neutered specimens was successful. The genetic control method is characterized by selectivity, its use is not associated with a negative impact on the environment and does not contribute to the emergence of resistance to sterilization factors.