White mushroom main features of taxonomy. Morphology and taxonomy of fungi. Economic importance of mushrooms

Mushrooms are divided into two groups:

Mixomycota (slime mushrooms);

Eumicotas (true mushrooms).

Real mushrooms are divided into 6 classes:

1 – chytridiomycetes

2 – oomycetes

3 – zygomycetes

4 – ascomycetes

5 – basidiomycetes

6 – deuteromycetes.

The division of real mushrooms into classes is based on 2 characteristics: the type of mycelium, features of sexual and asexual reproduction. The first three classes of fungi have unicellular mycelium, i.e. these are lower mushrooms. The last three classes are the highest (multicellular mycelium).

In terms of reproduction, the first five classes are perfect mushrooms, because They have both sexual and asexual reproduction. Deuteromycetes have lost sexual reproduction - imperfect fungi.

Each class of fungi is divided into genera and species. The name of mushrooms is double - it consists of the name of the genus and species.

21. Chytiridiomycetes are a class of molds.

The mycelium is poorly developed, unicellular. Asexual reproduction by zoospores with 1 flagellum. Sexual reproduction is by various types of zygotospores.

22. Oomycetes are a class of molds.

The mycelium is unicellular developed. Asexual reproduction by zoospores with 2 flagella. Reproductive – oospores.

23. Zygomycetes are a class of mold fungi.

The mycelium is unicellular, well developed. Asexual reproduction by immobile sporangiospores. Sexual – zygospores

They include 3 main genera:

1. Mukor (Mucor)– typically 1-2 large sporangiocartes with large sporangia, develops well. There is bread mold on the bread.

2. Rhizopus ( Rhizopus)- sporangiophores come out in bushes, have smaller sporangia and something like root hairs - rhizomes, with the help of which the fungus is attached to the substrate. This fungus is called capitate mold due to the fact that mature sporangiospores are clearly visible in the form of black heads on the nutrient substrate. Spoils many food products and causes soft rot of berries.

3. Tamnidium (Thamnidium) – has a large central sporangium with sporangium. Smaller sprangia, called sporangioles, extend from the sporangiolus.

24. Ascomycetes are a class of molds. Fruit marsupial axcomycetes.

The mycelium is multicellular, well developed. Asexual reproduction by conidia. Sexual - ascospores. Depending on the location of the ask, the class is divided into 2 subclasses:

1 – fruit marsupial ascomycetes (asci ripen in special fruiting bodies formed by fused mycelial hyphae).

Fruit marsupials:

1 – leukin mushrooms or fungi belonging to the genus Aspergillus. The fungus Aspergillus niger is used for the industrial production of citric acid. Aspergillus oryzae, Aspergillus awamori, Aspergillys batatum are used to obtain mold enzymes that are used in industry. They also cause rapid spoilage of food products and an allergic disease - aspergillosis.

2. Carpal fungi, fungi of the genus Penicillium. Penicillium notatum is used to produce the antibiotic penicillin. Penicillium roqueforti (Roqueforti), Penicillium camemberi are used in the production of Roquefort and Camembert cheese. Fungi of this genus cause molding of food products and allergic diseases - penicillosis.

25. Basidiomycetes are a class of mold fungi.

The mycelium is multicellular, well developed. Reproduction is asexual - by conidia (rare). Sexual - by basidiospores, which mature on unicellular and multicellular basidia.

The class is divided into 2 subclasses:

1 – basidiomycetes with unicellular basidia;

2 – basidiomycetes with multicellular basidia.

Cap mushrooms– the mycelium is in the soil; a fruiting body in the form of a cap, stem, saucer develops on the ground, which is formed by fused hyphae of the mycelium. On the reverse side of the cap, basidia with basidiospores mature. Cap mushrooms grow in the vicinity of strictly defined trees. This happens because the mycelium of the fungus entwines the roots of trees, forming mycorrhiza or fungal root. Mycorrhiza is a symbiotic or mutually beneficial cohabitation of a fungus and a tree. The tree supplies the fungus with carbohydrates that the fungus cannot synthesize, and the mushrooms supply the tree with water and minerals.

Brownies– active destroyers of dead wood, i.e. wooden structures, barrels, boxes, floors, etc. For development, it requires high air humidity, while droplets of liquid may appear on the mycelium, it seems that the mushroom is crying, it is called a crying mushroom. It spreads quickly over long distances due to the formation of micellial strands.

Smut– fungi that parasitize cereal crops and cause the disease smut. Smut can be hard or wet (caused by the fungus Tillecia tritiki) and dusty (caused by the fungus Ustilago tritici). Smut fungi cause enormous damage to agriculture and impart toxic properties to grain; their content is strictly regulated.

26. Deuteromycetes are a class of mold fungi.

The mycelium is multicellular, well developed.

Asexual reproduction by conidia.

There is no sexual reproduction (imperfect).

Representatives:

1. fungi of the genera Aspergillus and Penicylium that have lost sexual development;

2. mushrooms of the genus Fusarium;

3. mushrooms of the genus Alternaria;

4. fungi of the genus Cladosporium;

5. milk mold Oidium lactis;

6. Botrytis tree mold.

Fungi are a group of microorganisms widespread in nature. Some fungi are active agents of spoilage of food products, goods and materials of organic origin (paper, wood, fabrics, leather goods), others are used in industry for the production of cheeses, fermented milk products, for pickling vegetables, for the production of various organic acids, enzyme preparations, antibiotics etc.

The structure of mushrooms . The vegetative body of most fungi is a mycelium or mycelium, consisting of thin intertwining threads called hyphae. Such fungi are called filamentous (they are also called mold).

Fungal hyphae can be straight, curved, spiral-shaped, with swellings or thickenings, with depressions and short processes “roots” that serve for attachment to the substrate. The surface of the hyphae can be spiked, smooth, reticulate, fibrous, and sometimes folded. The diameter of the hyphae ranges from 2 to 50 micrometers or more.

Depending on the structure of the mycelium, fungi are divided into higher (representatives of the classes of ascomycetes and deuteromycetes) and lower (class of phycomycetes). In higher fungi, the hyphae are separated by partitions (septa), in the center of which there is a large pore.

Mushrooms are cynocytic microorganisms. This means that they grow and at the same time nuclear divisions occur, but cell divisions do not occur. Thus, the vegetative body of the fungus is one large multinucleate cell.

Figure 5 – Fungal hyphae: a – nonseptate; b – septate.

All microscopic fungi can reproduce vegetatively from a piece of mycelium.

Fungal cell structure .

Fungi have a eukaryotic cell type.

The cells of most fungi have the following structure:

Dense multilayer cell wall, consisting of 80-90% polysaccharides (the main polysaccharide is chitin, some have cellulose, proteins, lipids, and polyphosphates are present in small quantities). The cell wall performs a support-mechanical and protective function;

Under the cell wall there is a three-layer cytoplasmic membrane;

The cytoplasm contains numerous organoids;

- mitochondria– formations from lipoprotein membranes in which energy processes are carried out and adesine triphosphamide (ATP) is synthesized, a substance rich in energy;

- endoplasmic reticulum(endoplasmic reticulum) - a membrane system of interconnected tubules (in some places narrowing or expanding). It penetrates the cytoplasm and is associated with the cytoplasmic membrane and the nuclear membrane. The synthesis of many substances (lipids, carbohydrates, etc.) takes place here;

Figure 6 – Diagram of the structure of a fungal cell: 1 – endoplasmic reticulum; 2 - mitochondria; 3 – cytoplasm; 4 – cell wall; 5 – core; 6 – nuclear membrane; 7 – cytoplasmic membrane; 8 – ribosomes; 9 – Golgi apparatus; 10 – lysosomes.

- Golgi apparatus- a membrane system associated with the nuclear membrane and endoplasmic reticulum. Functions – transport to the nucleus of substances synthesized in the endoplasmic reticulum, removal of metabolic products from the cell;

- ribosomes– very small, round, numerous formations. Some are in a free state, some are attached to membranes. Protein synthesis occurs in ribosomes;

- lysosomes- small round bodies covered with a membrane. They contain enzymes that digest (break down) proteins, carbohydrates, and lipids coming from outside;

- core– (or several nuclei) is surrounded by a double membrane. The nucleoplasm contains the nucleolus and chromosomes containing DNA. The nuclear envelope contains pores that ensure the transport of substances between the nucleus and the cytoplasm;

- vacuoles- cavities surrounded by a membrane. Filled with cell sap and inclusions of reserve nutrients (volutin, glycogen, fat).

Mushroom propagation.

A feature of mushrooms is a wide variety of methods and organs of reproduction.

The same fungus can have several forms of reproduction. At the same time, the appearance of the mushroom changes so much that in each of them the mushroom is considered as an independent species.

Fungi, unlike bacteria, have three main methods of reproduction: vegetative, asexual and sexual.

Vegetative Reproduction occurs by budding, division and parts of the mycelium. During division, special fragments can be formed - oidia (arthrospores), which are formed as a result of the dismemberment of hyphae growing on a nutrient substrate into a mycelium. Fungi also reproduce by vaults, which, once on a nutrient substrate, germinate and form hyphae.

Chlamydospore cells (smut), which are formed on hyphae and are resistant to unfavorable conditions, take part in vegetative propagation.

The organs of asexual and sexual reproduction of fungi are diverse in structure and nature of formation and are the basis for their classification.

With asexual During reproduction, specialized cells are formed - spores, and with their help reproduction is carried out. Spores are formed at the ends of special hyphae, which have a different structure than other hyphae.

A

b

V

G

Figure 7 - Morphological features of mushrooms of various classes:

a - Mucor; b - Penicillium; c - Aspergillus; d – Alternaria.

In ascomycete fungi, external spores develop at the ends of such hyphae, located singly, in a group or in a chain. These disputes are called conidia, and the hyphae bearing them - conidiophores. After maturation, the conidia fall off and, under favorable conditions, give rise to a new mycelium.

In phycomycete fungi, spores are formed inside round cells called sporangia, the spores contained in them are called sporangiospores. Sporangia develop at the ends of hyphae called sporangiophores. Ripe sporangia burst and spores spill out of them, which, under favorable conditions, germinate into hyphae and form a new mushroom.

Deuteromycetes can reproduce by multicellular conidia.

Figure 8 – Conidiophores of imperfect fungi: a – Botrytis; b – Fusarium; c – Alternaria; d – Cladosporium.

Mushrooms produce a huge number of spores that can be transported by air currents over considerable distances.

Conidia and sporangia have different shapes and colors, due to which the mushrooms take on the appearance of colored plaques during sporulation. And the differences in the structure and appearance of conidiophores and sporangiophores are used to recognize fungi.

At the core sexual reproduction lies the fusion of two sex cells - gametes - with the subsequent union of their nuclei. The process takes place in three stages: plasmogamy, karyogamy, meiosis.

Plasmogamy is the fusion of cells and the bringing together of nuclei.

Karyogamy is the fusion of nuclei into one diploid nucleus.

Meiosis is the division of a diploid nucleus and the restoration of a haploid (simple), unpaired set of chromosomes in the nuclei.

As a result of this fusion, the so-called zygospore(when two outwardly identical cells merge) or oospore(when male and female cells merge). Under favorable conditions, zygospores and oospores germinate into new mold.

Higher multicellular fungi form basidia And ascospores.

Basidiospores develop at the upper end of a special sac-like cell - the basidium, and ascospores - in a cylindrical cell - the ascus (bag).

Basidia and asci most often develop in groups or layers in special fruiting bodies consisting of tightly intertwined hyphae. The caps and stems of edible mushrooms are the fruiting bodies.

Commodity classification edible mushrooms is based on the difference in the structure and location of the reproductive organs of fungi.

Fungi that can reproduce asexually and sexually are called perfect. Fungi that reproduce only asexually and are not capable of sexual reproduction are called imperfect.

Some fungi are capable of forming special cells, which are the resting stages of fungal development. For example, ergot forms sclerotia, which often infect cereal ears.

Sclerotia They are dark-colored solid formations of tightly intertwined hyphae. They contain a small amount of water, but are rich in reserve nutrients. Sclerotia are resistant to external influences, and under favorable conditions they germinate and form new mycelium.

Figure 9 – Sclerotia of fungi: a – sclerotia of Rhizoctonia; b – sclerotium of Papulaspora; c – sclerotium of Claviceps purpurea.

The smut fungus forms chlamydospores - dense, separate sections of hyphae covered with a thick membrane. Smut also attacks cereal plants. Chlamydospores form entire clusters in the ears in the form of black dust. Like sclerotia, under favorable conditions they germinate and give rise to a new fungus.

Taxonomy of fungi

All fungi, united in the kingdom of Fungi (Mycota or Myceta), are divided into two divisions: slime fungi (or myxomycetes) and actual (or true) mushrooms (eumycetes).

In taxonomy (classification) true mushrooms the main features are: the structure of the mycelium and the types of sexual and asexual reproduction.

True fungi are divided into five classes: chytridiomycetes, oomycetes (phycomycetes), ascomycetes, basidiomycetes and deuteromycetes (imperfect fungi).

Chytridiomycetes (archymycetes). They number about 300 species, the mycelium is absent or underdeveloped. They reproduce asexually (zoospores), using spores produced in sporangia.

Oomycetes (phycomycetes). The mycelium is highly developed, noncellular, multinucleate. Asexual reproduction using zoospores with two flagella. During the sexual process, oospores are formed. Includes about 700 species of mushrooms.

Representatives of this class are late blight, plasmapara and mucoraceae (rhizopus and mucor).

Late blight, or potato fungus, affects potato tubers and tops, as well as tomatoes and eggplants. A whitish fluffy coating forms on the surface of the affected areas, which is a cluster of sporangiophores. Ripe sporangia release spores that can infect healthy vegetables. Phytophthora can overwinter in the soil, forming oospores and chlamydospores there.

Plasmocoupler causes a grape disease called mildew. The fungus penetrates the grape cells and causes their death. The tissue of the affected grapes becomes brown in color and becomes covered with a cobwebby coating consisting of sporangiophores of the fungus. The plasmapara also produces oospores that can survive for several years.

Figure 10 – Plasmopara viticola mushroom on the underside of a grapevine leaf

Mukor(capitate mold) – the mycelium is loose-felt, white, grayish-white, later turning brown or grayish. Has nonseptate mycelium. They reproduce asexually and sexually with the formation of sporangiophores. Mucor is a common food spoilage agent; it often affects baked goods, fruits and vegetables, grows on the surface of wet grain, malt, Mucor nigricans is the causative agent of sugar beet rot, and develops on damp walls of warehouses. Among the mucor fungi there are representatives that cause diseases in animals (mucormycosis) and humans.

Many mucor fungi are capable of fermenting sugary substances with the formation of alcohol and organic acids and are used in the food industry, as well as for the production of enzyme preparations, carotenoids, and steroids.

Rhizopus forms capitate mold. Widely distributed in nature, soil, plant debris, and feed. Causes spoilage of fruits and vegetables.

Ascomycetes(fruit-bearing mushrooms). They have multicellular septate mycelium. Asexual reproduction occurs with the help of conidia; during the sexual process, asci (bags) are formed on special fruiting bodies, which contain 8 ascospores. This class has a huge number of species - about 30 thousand. Many of them infect cultivated plants and cause food spoilage. A number of ascomycetes find technical application.

Ascomycetes include Aspergillus, Penicillium, Sclerotinia, Venturia, and Ergot. Yeasts (yeasts) are also members of this class of fungi, but they are treated separately due to their particular technical importance.

Figure 13 – Fungus Rhizopus nigricans: 1 – sporangia; 2 – sporangiophores; 3 – rhizoids; 4 – stolons; 5 - disputes

Aspergillus(yellow, olive, black mold) causes spoilage of food products of animal and plant origin. There are more than 200 species. They decompose proteins, fats, polysaccharides. Aerobes. They play an important role in the mineralization of organic substances and cause molding of many foods.

Figure 14 – Aspergillus fungus: a – conidia; b – mycelium; c – formation of a conidiophore with conidia; d – formed conidia with conidiophores.

Some species of aspergillus are used to produce citric and itaconic acids, enzymes, and are used instead of malt in the production of alcohol. There are pathogenic forms (aspergillosis).

Penicillium(green, blue, gray mold) has a racemose structure of conidiophores and is therefore also called racemose. About half of all mold fungi belong to this genus and are found in the soil and air of poorly ventilated rooms. Produces a characteristic musty odor. When drying grain and flour, the smell turns musty. It affects many food products - dairy and meat products, sausages, fruits, materials, etc., and develops on the walls of damp rooms.

Some types of penicillium are used to obtain a valuable medicinal drug - penicillin, which is used for purulent and inflammatory processes. One of the clusters plays an important role in the ripening of Roquefort and Camembert cheeses.

Figure 15 – Penicillium mushroom: a – conidia; b – mycelium; c – formation of a conidiophore with conidia; d – formed conidia with conidiophores.

The ascomycetes include sclerotinia, which causes white rot of fruits and vegetables (carrots, melons, etc.). Sclerotinia mycelium penetrates the affected product and forms a white flaky coating on the outside.

Ergot affects cereal crops and sharply reduces their yield. Flour obtained from grain affected by ergot sclerotia is poisonous because the sclerotia contain toxic substances.

Venturia is the cause of scab in apples and pears. The disease manifests itself on fruits in the form of velvety olive-colored spots; the fruits do not ripen and take on an ugly shape.

Ascomycetes also include edible mushrooms: truffles, morels and strings.

Basidiomycetes. These are higher mushrooms with multicellular mycelium. They reproduce mainly sexually with the formation of basidia with basidiospores. Asexual reproduction occurs with the help of conidia.

Basidiomycetes form a large group that includes more than 20 thousand species of fungi.

The group of basidiomycetes includes cap mushrooms, polypores, house mushrooms, smut and rust fungus; they produce fruiting bodies.

Figure 16 – Ergot (Claviceps purpurea): a – rye ear with sclerotia; b – capitate stroma grown on sclerotia; c – section of the stroma (numerous perithecia are located along the periphery); d – perithecia with elongated club-shaped bursae; e – bag with eight filamentous spores.

Cap mushrooms have radially arranged plates on the underside of the cap (honey mushroom, champignon, milk mushroom, etc.) or tubes (ceps, boletus, boletus, etc.). Basidia are found on the surface of the plates and inside the tubes. Among the cap mushrooms there are poisonous ones (fly agaric, toadstool, etc.).

The mycelium of cap mushrooms develops in the soil or is partially embedded in the root system of plants.

Polypores- wood destroyers. It affects both living plants and wooden structures and buildings. Polypores cause great damage to wooden buildings, especially in conditions of sufficient humidity. On affected trees, hard, hoof-shaped fruiting bodies form in the form of growths. The fungus penetrates the tree trunk and uses the contents of the cells, as a result of which the wood is destroyed.

Figure 17 - Polypore

Brownies mushrooms are active destroyers of wooden parts of buildings. The house fungus forms white cotton-like mycelium on the affected wood.

Rust mushroom- a pest of various cultivated plants (cereals, sunflowers, etc.). The fungus forms rusty spots on the affected parts of plants, as it contains droplets of rust-colored oil in the mycelium and spores.

According to your position mushrooms- (lat. Fungi or Mycota) occupy a special place in living nature and are distinguished into a separate, independent kingdom of living organisms. And if the term Fungi is an international name mushroom kingdom, then Mycota is more of a scientific term that is found in biology, biochemistry, mycology and pharmaceuticals. According to a number of characteristics, this kingdom occupies an intermediate position between the kingdoms of plants and animals, and for its correct taxonomy, all organisms related to fungi are now divided into 3 independent evolutionary trunks and distributed among 4 kingdoms of living nature:

real mushrooms(Fungi) pseudofungi(Protozoa) mushroom-like protozoa(Protista) protozoa(Chromista)

Taxonomy of fungi- this is the section in mycology, dealing with the natural classification of fungi. The principles of taxonomy in mycology are based on the general principles of biological classification. Thus, fungi are one of the most difficult objects for taxonomy and especially for the development of a natural (phylogenetic) system. Phylogenetics- the field of biological systematics that studies the identification (definition or clarification) of evolutionary relationships among different species of living nature, both present and extinct. Scientific ideas about fungi, their origin and place in the system of the living world developed intensively and often changed throughout the entire period of study of these organisms. And this was reflected in their taxonomy. The biodiversity of fungi in wildlife is quite impressive and, according to taxonomists, is about 1.5 million, of which only about 4% have been studied so far. Components taxonomy of fungi are: nomenclature , taxonomy And classification . Taxonomy of fungi is the science of their classification. But before classifying mushrooms, they need to be studied well and correlated with certain categories, the so-called - taxa(species, genera, families, orders, classes, divisions, groups). A mushroom nomenclature- this is the prerogative of the International Code of Botanical Nomenclature and it is adopted at each regular International Botanical Congress. The last such Congress took place in 1999. Mushrooms(lat. Fungi or Mycota) - the kingdom of living nature, uniting organisms whose cells contain nuclei that combine the characteristics of both plants and animals. Science studies mushrooms mycology, which is considered a branch of botany, since mushrooms were previously classified as part of the plant kingdom. Back in the 18th century, the Swedish physician and naturalist Carl von Linnaeus (1707 - 1778), the creator of a unified system for classifying flora and fauna, in his work “System of Nature,” already expressed doubts about the placement of fungi in the plant kingdom. And his compatriot, botanist and mycologist Elias Magnus Fries (1794 - 1878), also the “creator of mycology,” proposed in 1831 to distinguish mushrooms into a separate kingdom. But the final understanding of mushrooms as a separate world was formed in science only in the 70s of the 20th century, when rich data on genetics, cytology and biochemistry were accumulated. Thus, the scientific term itself mushrooms at the beginning of the 21st century and became the name of a group in the biological classification, consisting of discrete objects united on the basis of common properties and characteristics of one of the kingdoms of living nature. The biological and ecological representation of fungi is too large and, therefore, it is one of the most diverse systems of living organisms, which has become an integral part of all terrestrial and aquatic ecosystems. According to modern estimates, there are from 100 to 250 thousand, and according to some estimates, from 1.5 to 2 million species of mushrooms on our planet. By now, the concept kingdom of mushrooms, combines 3 groups of mushrooms , which describe more than 4 departments of mushrooms , about 36 classes of fungi , over 140 orders of mushrooms , more than 560 fungal families , more than 8,280 fungal genera (and 5,100 generic synonyms for them), more than 97,860 types of mushrooms .

Methods for classifying mushrooms.

Mushrooms have always been very difficult systematize(that is classify). Classification implies a strict division of mushrooms into certain, clearly demarcated nomenclatures, the so-called taxa. These items are distributed hierarchically in an organized and orderly system. Or, in other words, they are mutually subordinate and located at different levels, the so-called ranks. Therefore, at present, mushrooms are classified as an independent kingdom of living nature, but during the period of creation and formation of taxonomy of fungi, they were classified as plants. This explains the fact that in the taxonomy of fungi there is the same taxa (delimited nomenclatures) as in plants: these are groups , departments , classes , orders , families , childbirth And kinds . Modern mycology suggests the following (science-based) classification of mushrooms. Mushrooms in nature are combined into kingdom of mushrooms , which in turn consists of: --> groups of mushrooms ; --> departments of mushrooms ; --> classes of fungi ; --> orders of mushrooms ; --> mushroom family ; --> fungal genera ; --> types of mushrooms , combining many subdivisions, subclasses, subgroups, etc.

But such a scientific interpretation of the classification of the mushroom world may seem interesting only to theorists or competent specialists. And, based on this, for ordinary mushroom pickers (that is, practitioners), we tried to simplify this scientifically based taxonomy of mushrooms and streamlined it to what is necessary and sufficient for any non-specialist, according to which: all mushrooms combined into a separate kingdom of mushrooms we propose to distribute it to: --> orders of fungi ; --> discharges of mushrooms ; --> mushroom sections ; --> fungal subgroups ; --> types of mushrooms ; --> mushroom categories ; --> mushroom seasons , which, just as in the case of a scientifically based method of systematizing mushrooms, should be divided into their characteristic components.

If, for someone, a scientifically based interpretation of the facts of the classification of mushrooms may not seem at all interesting, and a vitally applicable (applied) formulation of the system of the mushroom world may become more useful, then for convenience and to avoid confusion, such a “simplified” taxonomy mushrooms are considered in a separate left side menu with red buttons. And we can only hope that relying on this classification it will be much easier to understand the complex world of mushrooms. But if someone is not satisfied with it, then there is the opportunity to offer your own, different, unique taxonomy of the mushroom world, looking at which you will not want to object! Well, for everyone else who would still be interested in the scientific approach to the issue of taxonomy of fungi, we have the opportunity to familiarize ourselves with the pages of this section, which, albeit not completely, but still covers the most important and interesting aspects of the concept - scientific mushroom classification.

Classification(from Lat. classis - rank (class) and Lat. facere - to do) is a system of subordinate concepts (classes of objects) of any field of knowledge or activity, used as a means of establishing connections between these concepts or classes of objects. Scientific classification expresses a system of laws inherent in the area of ​​reality reflected in it. Distinguish natural classifications, the basis of which is the essential characteristics of objects (like the periodic system of chemical elements of D.I. Mendeleev), and artificial classifications(or auxiliary classifications), the basis of which is non-essential features (such as alphabetical subject indexes or name catalogs in libraries).
Classification is the distribution of objects into categories, classes, groups, with the condition that objects that have a common characteristic fall into one category, group, class. A taxonomy(in particular, biological systematics) is a scientific discipline whose tasks include the development of the very principles of classification of living organisms and the practical application of these principles to the construction of the very system of their taxonomy.

The division of fungi into classes is based on the use of a set of characteristics; The leading factors are the structure of the mycelium and the types of sexual and asexual reproduction.

The main classes of fungi are chytridiomycetes, oomycetes, zygomycetes, ascomycetes, basidiomycetes and deuteromycetes (imperfect fungi). For each class, mushrooms that are common agents of food spoilage or used in industry are given (as examples).

Chytridiomycetes. Mycelium at they are poorly developed or absent, and the body is a bare protoplast. Chytridiomycetes reproduce mainly asexually through motile spores with one flagellum - zoospores, developing inside zoosporangia.

The sexual process is varied; In some mushrooms, as a result of the sexual process, an oospore is formed, in others, a zygospore.

Synchytrium endobioticum is the causative agent of potato tuber cancer (Fig. 13). On the affected tubers, dark lumpy growths (tumors) of various sizes, resembling a sponge, form near the eyes. The growths contain a mass of zoospores of the fungus, which are released from the collapsing tissues of the tuber and infect other tubers.

This can happen many times during the summer. In autumn, dormant cysts form in the tubers, which can remain in the soil for many years. In the spring, under favorable conditions, they germinate, forming zoospores that infect young plants. Yield losses can be up to 40–60%. The main control measures: breeding resistant varieties and soil disinfection.

Oomycetes. Their mycelium is well developed, noncellular, multinucleate. Asexual reproduction occurs

with the help of zoospores with two flagella developing in zoosporangia. During the sexual process, oospores are formed.

Late blight and plasmamopar are of greatest importance.

Late blight (Phyto-phthora infestans), or potato fungus, affects potato tubers and tops (see p. 228 and Fig. 39). On short branched sporangiophytes, ovoid or lemon-shaped sporangia develop. In a humid environment, several motile zoospores are formed in them, which then grow into hyphae. In a dry environment, zoospores are not formed; the sporangium directly germinates into the hypha. Late blight also affects tomatoes and eggplants. Plasmopara viticola is a fungus that causes a grape disease called mildew or downy mildew. The fungus attacks leaves and berries. The affected berries turn brown, become covered with a cobwebby coating consisting of fungal spores, wrinkle and fall off. The development of the disease is favored by high air humidity. Plasmopara oospores overwinter in the soil and can remain viable for several years.

Zygomycetes. Their mycelium is well developed and non-cellular. Asexual reproduction occurs with the help of immobile sporangiospores; sexual reproduction is by zygospores. This class includes mucoraceae mushrooms, which are widespread in nature.

Mucor fungi are characterized by a diverse structure of asexual sporulation organs. In some (for example, tamnidium - Fig. 14, V) Along with large multisporous sporangia, there are also small sporangia with a small number of spores - sporangioles. Many mucor fungi are causative agents of spoilage of various food products. They develop on foods in the form of a fluffy white, gray mass. The most important of the mucor fungi are mucor and rhizopus.

Fungi of the genus Mucor have large sporangia formed on single, simple or branching sporangiophores (Fig. 14, A). Species of this genus differ from each other in the shape and color of sporangiospores, in the shape of chlamydospores, etc.

Fungi of the genus Rhizopus (Rhizopus) form non-branching, dark-brown sporangiophores, growing in bunches (bushes). At the base of the latter there are root-like formations - rhizoids (Fig. 14, b), with the help of which the fungus attaches to the substrate. The sporangia are large with dark-colored spores and appear as black “heads” on the sporangiophores, which is why Rhizopus has received the name “capitate mold.” Rhizopus spreads across the substrate very quickly with the help of long creeping hyphae (stolons), reminiscent of strawberry mustaches. By attacking berries and vegetables, the fungus causes “soft rot” - complete destruction of tissue.

Some mucor mushrooms have a positive effect due to their ability to produce organic acids, enzymes, and ferment sugar into ethyl alcohol. In Eastern countries, they are used along with yeast in the production of alcoholic beverages and in the manufacture of specific food products fermented from soybeans.

Rice. 13. Potato cancer

Rice. 14. Sporangiophores of zygomycetes:

A - Mucor; b– Rhizopus; V– Thamnidium

Ascomycetes. Ascomycetes, or marsupial fungi, differ in structure and properties.

The majority of mycelium is well developed and cellular, but ascomycetes also include organisms without mycelium, represented by single budding cells. They all have, however, a common origin and a number of common structural features.

Asexual reproduction of mycelial ascomycetes - with the help of conidia. Conidial sporulation is varied. Conidiophores are formed on the mycelium singly or in groups, forming coremia, pycnidia, and a bed (see p. 27). During the sexual process, ascospores are formed in bags (asci). Bags develop in many fungi in fruiting bodies of various shapes and structures, characteristic of individual representatives of ascomycetes. Some marsupial fungi do not have fruiting bodies, and their bags develop directly on the mycelium. Mushrooms that form fruiting bodies are called fruiting bodies, and mushrooms that do not form such bodies are called gymnastics.

In some marsupial fungi, conidial sporulation is unknown; in others, it predominates in the development cycle. In nature (on food products), marsupial fungi are found only in the conidial stage; they have an independent name and are considered in the class of imperfect fungi (see p. 36).

Many vocal mushrooms have true mycelium. This is, for example, Eremothecium ashbyi, used for the industrial production of vitamin Bj. In other vocal fungi, the mycelium partially disintegrates into arthrospores. There are fungi that are single budding cells.

The most important representatives of non-mycelial gymnasium fungi are yeasts (see p. 38).

To the group fruit marsupials included some species of widespread fungi of the genera Aspergillus and Penicillium, capable of marsupial sporulation. Their fruiting bodies are in the form of small balls formed from tightly intertwined hyphae. Inside these spherical bodies there are bags with spores (see Fig. 15, c, d). Most species of Aspergillus and Penicillium are found only in the conidial stage and belong to the class of imperfect fungi (see p. 36).

Fungi of the genus Aspergillus (Aspergillus) have unicellular, unbranched conidiophores. The apices of the conidia-bearers are more or less swollen and bear on their surface sterigmata arranged in one or two tiers with chains of conidia (Fig. 15, A). Conidia of various colors (greenish, yellow, brown), often round. The conidiophore is similar in appearance to a mature dandelion.

Fungi of the genus Penicillium have multicellular, branching conidiophores. At the ends of the branches of the conidiophore there are sterigmata with chains of conidia. Conidia can be green, blue, gray-green or uncolored. The upper part of the conidiophore (Fig. 15, b) in the form of a brush, of varying degrees of complexity, hence the name of the mushroom - penicillium (tassel).

Aspergillus and penicillium fungi are common pathogens causing spoilage (mold) of food products, industrial products and materials. Some representatives are used in industry. Asp. niger, for example, is used in the production of citric acid; Asp. oryzae and Asp. awamori is used to obtain enzyme preparations.

Certain species of Penicillium are used in the production of the medicinal drug penicillin. Pen. roqueforti plays an important role in the ripening of Roquefort cheese, Pen. camemberti – in the production of Camembert cheese.

Rice. 15. Conidiophores and fruiting bodies (cleistothecia) of fungi:

c – Aspergillus; b – Penicillium; c, d – fruiting bodies (general view and section)

Some aspergilli cause diseases - aspergillosis (respiratory tract, skin, oral mucosa) in humans and animals. There are species that secrete substances that are poisonous to animals and humans - aflatoxins (coumarin derivatives), one of the biological effects of which is tumor formation.

Sclerotinia is a common and dangerous causative agent of white rot of fruits and vegetables during storage (see p. 230). Sclerotinia mycelium permeates the affected organ, forming a white flocculent coating on its surface. As the name indicates, these fungi are characterized in their development cycle by the formation of sclerotia on the mycelium. There is no conidial sporulation.

Fruit-bearing mushrooms also include truffle and morel mushrooms, the fruiting bodies of which are eaten, as well as strings, which are considered conditionally edible, because some of their species are poisonous. Truffles form underground, tuberous fruiting bodies of a fleshy or gristly consistency, dark in color, reaching the size of potato tubers. The fruiting bodies of morels are large, fleshy, consist of a stem and a cap, with a folded brown surface, where bags with spores are located in layers. Ergot alkaloids are used in medicine.

Basidiomycetes. These are higher mushrooms with cellular mycelium, some of which have perennial mycelium. Asexual reproduction (by conidia) is rare. The organs of sexual reproduction are basidia with basidiospores. In some fungi, the basidia are unicellular, in others they are multicellular (see Fig. 12, 1, 2). Single-celled cylindrical or club-shaped basidia bear one basidiospore on four short processes (sterigmata). Multicellular basidia consist of four cells, which contain one basidiospore per sterigm. Basidia with basidiospores can develop directly on the mycelium, but many basidiomycetes have fruiting bodies.

Basidial fungi with unicellular basidia widely distributed in nature. Most of them live in the soil, on plant debris, some on trees. Most basidia with basidiospores develop in layers on or inside the fruiting bodies. The structure, shape and consistency of fruiting bodies are varied and characteristic of different types of mushrooms. This group of basidiomycetes includes cap and tinder fungi.

Cap mushrooms have an annual fleshy fruiting body consisting of a cap and a stalk. The lower surface of the cap consists of radially diverging plates (for example, in russula, honey mushroom) or from numerous tubes (in porcini mushroom, boletus, etc.). On the lateral surfaces of the plates and on the inner walls of the tubes there are basidia with spores. Many cap mushrooms are edible. What are usually called mushrooms and eaten are the fruiting bodies; the mycelium lives in the soil. Some cap mushrooms are poisonous.

In the USSR and other countries, industrial cultivation of edible champignon mushrooms has been developed. In some countries (China, Japan) other agaric mushrooms are also grown. Currently, the method of growing mushroom mycelium in fermenters is becoming increasingly widespread. This method allows you to quickly accumulate a significant amount of mycelium, which in chemical composition and taste differs little from the fruiting bodies of the corresponding mushroom.

Polypore fungi are wood destroyers. Mycelium lives in wood, living (in the trunks and roots of trees) or dead (harvested, processed in buildings), destroying it. Fruiting bodies form on the surface of the affected wood. Most mushrooms are perennial and vary in shape, size, consistency and color. Fruit bodies are loose, dense, woody, in the form of crusts, hoof-shaped:

Many tinder fungi are known as brownies. They affect wooden parts of buildings, warehouses, and are found in wine cellars on wooden shelves, barrels and other objects. The most harmful of them is the true house mushroom (Serpula lacrymans), which is not found in nature and is found only in buildings. A cotton wool-like accumulation of mycelium with yellowish (or pinkish) films forms on the affected objects. The fruit body is fleshy-membranous. The wood softens and rots. With high air humidity, the fungus spreads very quickly, which is facilitated by the development of strands of fused hyphae up to several meters long. House mushrooms cause great economic damage to the national economy.

Smut and rust fungi cause great damage to agriculture.

Deuteromycetes, or imperfect fungi (Deuteromycetes). These are fungi with cellular mycelium in which sexual reproduction is not detected. Most of them reproduce by conidia. Conidiophores in different species have different appearances, located singly or in groups. Some fungi form oidia (arthrospores); there are forms without special reproductive organs. Conidia are varied in shape, structure, and color; they can be unicellular or multicellular.

Many representatives of imperfect fungi are ascomycetes, and possibly basidiomycetes, which have lost the ability to sexually sporulate, for example, many species of Aspergillus and Penicillium, which do not have a marsupial stage of development. Some of the fungi considered in this class are conidial stages of development of certain known ascomycetes. Thus, the fungal species Botrytis and Monilia described below are conidial stages of marsupial fungi of the Sclerotinia family.

The most common and dangerous pathogens causing food spoilage are the following fungi.

Fusarium has two types of conidia: macroconidia - sickle-shaped multicellular, which develop on short branched conidiophores (Fig. 16, b), and microconidia - smaller elliptical or rounded unicellular ones (or with one or two septa). The mycelium of these mushrooms is white, white-pink, yellowish. Fusariums cause diseases of various vegetables and fruits, known collectively as fusarium diseases. Some species of Fusarium attack potato tubers (see p. 238). There are species that produce substances that are poisonous to humans (see p. 154).

Rice. 16. Conidiophores of imperfect fungi:

A– Botrytis; b– Fusarium; V– Alternaria; d – Cladosporiura

Botrytis has tree-like branched conidiophores, bearing single-celled, smoky-colored conidia collected in heads at the ends of the branches (Fig. 16, c). This fungus attacks apples, pears, many vegetables, and especially berries. At the same time, their surface becomes covered with a fluffy gray coating, the tissues become watery, turn brown, and soften (see p. 234).

Botrytis, together with other fungi, causes agate rot of sugar beets.

Alternaria is characterized by the presence. multicellular dark-colored conidia of a club-shaped elongated shape, sitting in chains or singly on poorly developed conidiophores (Fig. 16, V).

Various Alternaria species are widely distributed in soil and plant debris. The fungus causes a disease of many agricultural plants, called alterna-p and o z o m. Developing on food products, alternaria forms black depressed spots on them (see p. 231).

Oidium forms branched white mycelium, the hyphae of which easily disintegrate into oidia (see Fig. 10, A).

One of the species of this genus - Oidium lactis (geotrichum candiclum) - milk mold, often develops in the form of a velvety film on the surface of pickled vegetables and fermented milk products during storage. The fungus uses the lactic acid found in these products, which leads to their spoilage. In dairy products, oidium decomposes proteins and fats. This mold is also found on compressed yeast, butter, cheese and other products.

Monilia is a mushroom that does not have true conidiophores. Conidia, connected in simple or branching chains, are located on short processes of the mycelium. These fungi are active causative agents of fruit spoilage (see Fig. 44 and p. 233).

Cladosporium has weakly branching conidiophores bearing chains of conidia at the ends (Fig. 16d). Conidia come in various shapes (round, oval, cylindrical, etc.) and sizes, often two-celled. Mycelium, conidiophores and conidia are olive green. These mushrooms are characterized by the fact that they release a dark pigment into the environment.

Cladosporium is often found during refrigerated storage on various food products in the form of velvety dark olive (to black) spots;