What is the reproduction of fungi by spores called? Features of mushroom reproduction. Sexual method of reproduction

In fungi, vegetative reproduction can be carried out by body parts or spores. Its most primitive form is reproduction by particles of hyphae, as well as sclerotia, fragments of cords and rhizomorphs. Separating from the mother mycelium and entering a favorable environment, they give rise to a new organism.

One of the forms of vegetative propagation is the formation of chlamydospores and oidia. Chlamydospores appear when the contents of certain mycelial cells become compacted and isolated. At the same time, they are covered with a dark-colored dense shell. Chlamydospores can persist for a long time in unfavorable conditions after separation from the mother hyphae cells. When they germinate, they form mycelium or sporulation organs.

Oidia appear after the hyphae disintegrate into individual segments; they are short-lived and equipped with a thin shell. Subsequently, they give rise to a new mycelium. One of their varieties is gemma with a denser dark shell that can be preserved in winter.

Some fungi reproduce by cell budding, a process characteristic of yeast fungi. At first they develop small outgrowths, gradually they increase in size and separate from the mother cell, after which they begin to bud. These cells are blastospores.

Reproductive propagation of fungi

Reproductive reproduction occurs with the help of spores; they can form on the surface of special organs or inside them. In their structure, spores differ from vegetative hyphae. Asexual reproductive reproduction occurs with the formation of spores; in sexual reproduction, the appearance of spores is preceded by the sexual process.

Most often, asexual reproduction begins on well-developed mycelium with sufficient nutrients. In this process, the spore-bearing organs are sections of hyphae or their special branches. The formation of zoosporangia is the most simple form asexual reproduction. Zoospores retain their properties only in water; they have one or two flagella with which they can move.

The sexual process of fungi is very diverse; in its simplest form, it is the fusion of two identical-shaped, heterosexual zoospores. Zygogamy and oogamy are more complex processes. In the first case, the contents of two outwardly identical germ cells of different sex mycelia are combined; with oogamy, germ cells of different structures are laid on the mycelium - oogonium (female) and antheridium (male). When their contents fuse, an oospore is formed.

The mushroom population numbers about 100 thousand. various types. Although some mycologists are of the opinion that the number of fungal species exceeds 1.5 million.

The prevalence of fungi is so great that they can be found not only on land, but also in water, and inside animals and plants.

All existing living organisms are divided into two categories - animals and plants. Mushrooms are classified as plants, although it would be correct to separate them into a separate category.

Fungi feed on animal or plant remains, and some species feed on the contents of cells and tissues of living organisms. As a result, fungi are classified as heterotrophic organisms (not capable of photosynthesis - forming organic substances from inorganic ones).

Among the many features of mushrooms, the following can be distinguished: the ability of the vegetative body for unlimited growth, reproduction through spores and immobility in the vegetative state.

Mushrooms are spore-bearing plants; they do not have roots, stems or leaves. Fungal cells are made of chitin and are colorless, while green plant cells are made of cellulose.

Mycelium - mycelium

What we are used to collecting and call mushrooms is fruiting body, and the fungus itself is located inside the soil or substrate consisting of cobwebby threads.

Substrate- this is the environment from which the mushroom receives nutrients.

The underground web is a mycelium or mycelium, and the threads are hyphae.

The functions of the fruiting body include species preservation and reproduction.

The fruiting body is formed by joining hyphae into dense balls that are constantly increasing. Gradually, the hyphal cells acquire order. At some point, when the cells begin to elongate, the fruiting body breaks through the substrate and its growth begins.

A certain part of the fruiting body is covered by a spore layer. According to its structure, the spore layer is divided into:

• lamellar (spores are on plates;
• tubular (spores are located inside the tubes);
• intrafruit (spores are formed inside the fruiting body. For example, in).

The hyphae of the outer layers are dark in color and have thickened walls. Their main purpose is protective functions. And the hyphae of the inner layers have thin walls. Their purpose is conductive functions.

They can also form resimorphs And mycelial strands, which, in turn, perform conducting functions. Resimorphs and strands are hyphae located in parallel and interconnected. Some of them can reach several meters in length.

Another modification of the mycelium is sclerotia- these are dense weaves of mycelium that protect it from unfavorable conditions.

Fungal reproductive organs are formed on mycelium, are the basis of fungal taxonomy and are very diverse in their structure.

Mushroom propagation process

Fungi reproduce vegetatively, asexually and sexually. Let's consider each of the methods of mushroom propagation in more detail.

1. Vegetative propagation occurs in parts of the mycelium. Part of the mycelium separates and continues to exist independently.

2. Asexual reproduction - This is reproduction by spores. Spores can be without flagella, with one flagellum, or with several flagella.

Spores without flagella are called conidia and are located on the conidiophore hyphae. And spores with flagella are called sporangium and are located on the hyphae-zoosporangium.

Because With the spore method of reproduction, the probability of the formation of a new mycelium is small, then the mushrooms release a huge number of spores (several billion) into the air, which are then carried by the wind.

In order for a new mycelium to be born, the spores must fall to the ground with suitable soil for their development and with favorable external conditions. But for the fruiting body to grow, it is still necessary for two spores of different sexes to take root in one place.

3. The result of spore reproduction is the primary mycelium. Secondary mycelium is formed by the fusion of two primary ones. This is what is called sexual reproduction .

In conditions favorable for development and growth, the secondary mycelium produces fruiting bodies. As in any living organism, mycelium cells contain all hereditary information. The process of accumulation of spores and their maturation occurs in the fruiting body of the fungus.

After full maturation, the spores are ready for their “flight” to generate new life in conditions favorable for this.

Kira Stoletova

To save money and get environmentally friendly products, people grow various crops, including mushrooms, in their dachas (using utility rooms for this purpose). They are easy to grow both in the garden and indoors. To effectively organize the growing process, you need to understand what mushroom propagation is and what the specifics of this process are.

Features of the structure of mushrooms

Before we talk about methods of reproduction of fungi, you need to understand what these organisms are. They combine some of the characteristics of animals and plants, which is why they were united into a separate kingdom - Mushrooms. After much debate, scientists who could not decide what species they should be classified as, assigned a separate kingdom to mushrooms.

Initially this group organisms lived in the waters of the oceans. After some time, for unknown reasons, they changed their habitat, moving to the forest. They are united with the kingdom of Plants:

• ability to reproduce by spores;
• absorptive method of nutrition;
• presence of a cell wall;
• the presence of vacuoles in the cell;
• unlimited growth, etc.

They are related to the kingdom of Animals:

• metabolic product - urea;
• absence of plastids (including chloroplasts);
• heterotrophic nutrition;
• the presence of chitin in the cell wall;
• reserve nutrient - glycogen, etc.

Not everyone has an idea about the structure of a mushroom. It consists of mycelium (mycelium, or vegetative body), which plays an important role in the process of reproduction, and the reproductive organs themselves. The mycelium is underground. It consists of thin, colorless threads through which nutrition occurs.

It is difficult to find another organism that could adapt so well to environmental conditions.

Mushroom propagation

Reproduction of mushrooms united into a separate large kingdom occurs in 3 ways:

• vegetative;
• asexual;
• sexual.

Those. they multiply with the help of everyone, known to science today's methods.

Vegetative method of propagation

This method is convenient to use when growing crops in the country, in the basement or on mushroom farms. Its essence lies in the division of the mycelium. Some parts of a certain size are separated from the main vegetative body and placed in an environment where they begin to develop separately. This is the most quick way, often found in the wild.

A feature of the vegetative propagation of fungi is that in many species arthrospores (oidia) and chlamydospores are formed. These cells give rise to new mycelium. Oidia are formed as a result of the breakdown of hyphae. Each such cell gives rise to a new mycelium. A special feature of chlamydospores is that these cells are covered with a dense membrane, sometimes colored in a color different from the color of the mycelium. This membrane stores nutrients that allow the cell to “wait out” unfavorable conditions. Chlamydospore remains viable for 7-10 years.

But division through the formation of oidia or chlamydospores is not considered a purely vegetative method. It is classified as a cross between vegetative and asexual reproduction of fungi.

Budding occurs when a new growth appears on the mycelium, which grows over time and becomes a separate organism. At first, the kidney has microscopic dimensions. Among higher organisms, budding is rare, but representatives of the lower class (yeast-like, for example) often use it.

Asexual method of reproduction

In the asexual method, fungi reproduce through microscopic spores. Propagation by spores is similar to using seeds, but planting material is more difficult to collect. Spores are carried not only by the wind, although they most often travel with air currents, but also stick to animal fur. The interesting thing is that these microscopic particles do not sink. When placed in a favorable environment, they develop, forming mycelium.

Spores can form inside or on the surface of spore-bearing organs. They also differ in structure. Some spores are equipped with flagella that allow them to move and are called zoospores. Others do not have such flagella; they are immobile and are called sporangiospores.

Irina Selyutina (Biologist):

Many lower fungi are characterized by the presence of motile zoospores. Zoospores develop in sporangia. Other lower fungi are characterized by sporangiospores that develop in sporangia. Sporangia sit on special hyphae that differ from other hyphae - sporangiocartes. They rise up from the substrate on which they developed. This elevated arrangement of sporangia facilitates the dissemination of spores by air currents after the sporangium shell has developed.

Asexual reproduction with the help of conidia has been described for marsupials, basidial, imperfect and a few lower fungi adapted to terrestrial existence. Conidia are covered with a membrane, they do not have flagella - organs of movement; distribution occurs with the help of air, insects, and humans.

An interesting thing is that the spores grow into copies of the parents with minor mutations.

Spores are intended only to increase the population.

If you look at the number of representatives of the kingdom, you can see that even with the asexual method of reproduction, significant changes in species occur. This is due to the fact that several generations grow over the course of a season, each of which has some changes. And ultimately, minor mutations of each generation lead to the emergence of new species.

Sexual method of reproduction

From the name it is clear that we're talking about about the merger process. During sexual reproduction of fungi, male and female cells (gametes) merge. But this happens in the second stage of reproduction. The first stage involves the formation of these cells. During the process of fusion, spores arise, from which a new organism is formed. In the asexual method, the formation of spores does not involve cell fusion, which is their difference. Cells intended for sexual reproduction may have the same appearance, or they may differ.

It is interesting that lower fungi that reproduce by cell fusion immediately produce a sexual spore. Representatives upper class They first form mycelium, which is somewhat different from that from which mushrooms emerge. This method is also typical for marsupial fungi. But in them, cell fusion occurs directly inside the bag (ascus). The cell formed inside the bag is capable of dividing and forming new spores.

The main role in reproduction by any means is played by the mycelium, which is located underground. If you harvest by cutting off the fruiting body, the mycelium remains intact, because you left part of the stem in the soil. Within 14-20 days it is able to grow a new fruiting body filled with spores. If, during harvesting, the fruiting body is pulled out of the ground (attention! it is pulled out, not twisted), the integrity of the mycelium is violated. It will take a lot of time to restore this organ. The duration of recovery depends on the area of ​​the damaged part of the mycelium.

In cap mushrooms, the spores are located under the cap (on its lower side). The part of the fruiting body where spore formation occurs is called the hymenophore. The layer with spores can be tubular or lamellar. Tubular type surface suggests the presence of many tubes tightly adjacent to each other, in which the spores are placed. It is impossible to see these tubes without a microscope, which is why the surface looks like a sponge. People call them not tubular, but spongy. The lamellar hymenophore is clearly visible without magnifying instruments. In addition to the types of hymenophores that are familiar to us, there are several more, but we usually use only two, known from school.

to the word grub, which meant “hump”, “hill”, “hillock”. For comparison, this is also where the name of the hump-nosed breeds of pigeons comes from - “mushroomy”.

In some Russian dialects, all mushrooms are called the word lips, but to a greater extent this applies to popular names some tinder fungi - “lips”, “sponges”. In this form the word passed into some Slavic languages, for example, in Czech ( hoby) and Slovak ( huby). Latin fungus comes from Greek σφογγος , also denoting a sponge, a porous body.

Another interpretation derives the word “mushroom” from the verb “row” (“row”) - when growing, the mushroom is “raked” out of the ground.

A connection with Old Russian is also possible glib- mucus, sticky substance (compare with the Lithuanian word gleivės, having the same meaning). This root passed into the South Slavic languages: Slovenian gliva, Serbian giva. In Ukrainian glyva- name of oyster mushroom.

Systematic position and origin

For a long time, fungi were classified as plants, with which they are similar in their ability to unlimited growth, the presence of a cell wall, adsorptive nutrition, for which they have a very large external surface (rather than phagocytosis and pinocytosis), and the inability to move. But due to the lack of chlorophyll, fungi are deprived of the ability for photosynthesis inherent in plants and have a heterotrophic type of nutrition characteristic of animals, they deposit glycogen, and not starch as a storage substance, the basis of the cell wall is chitin, not cellulose (except for oomycetes), they are used in metabolism urea - all this brings them closer to animals. They are distinguished from both animals and plants by the presence in many groups of a dikaryonic phase and perforations in the intercellular septum.

As a result, fungi have been recognized as a separate independent kingdom, although they have a polyphyletic origin from various flagellated and non-flagellate unicellular organisms. The latter gave rise to zygomycetes, from which higher fungi are derived. Oomycetes may have evolved from heteroflagellate algae. Forms close to modern ones appeared a very long time ago; spores similar to those of Saprolegniaceae are 185 million years old.

Structure

Most fungal cells have a cell wall; only zoospores and vegetative cells of some primitive fungi lack it. 80-90% of it consists of nitrogenous and non-nitrogenous polysaccharides; in most, the main polysaccharide is chitin, in oomycetes it is cellulose. The cell wall also includes proteins, lipids and polyphosphates. Inside there is a protoplast surrounded by a cytoplasmic membrane. The protoplast has a structure typical of eukaryotes. There are storage vacuoles containing volutin, lipids, glycogen, fatty acids (mostly unsaturated) and other substances. One or more nuclei. Different groups have different predominant ploidy stages.

Classification

There is currently no generally accepted classification of fungi, so the information given in the literature or other sources may vary significantly among different authors.

Asco-, basidio- and deuteromycetes are often grouped into the group Higher Fungi ( Dikarya).

Other small groups are also distinguished.

Role in biocenosis

Fungi can live in different environments- in soil, forest litter, in water, on decaying and living organisms. Depending on the method of consumption organic matter there are:

Meaning for humans

Food use

Edible mushrooms

IN food industry Various microscopic fungi are used: numerous yeast cultures have important for the preparation of vinegar, alcohol and various alcoholic beverages: wine, vodka, beer, koumiss, kefir, yoghurt, as well as in baking. Mold cultures have long been used to make cheeses (Roquefort, Camembert), as well as some wines (sherry).

Due to the high content of chitin in mushrooms, their nutritional value is low and they are difficult to digest by the body. However nutritional value The benefits of mushrooms lies not so much in their nutritional value, but in their high aromatic and taste qualities, which is why they are used for seasonings, dressings, in dried, salted, pickled form, and also in the form of powders.

Poisonous mushrooms

Mushrooms and preparations made from them are widely used in medicine. For example, in oriental medicine they use whole mushrooms - reishi (ganoderma), shiitake, cordyceps, etc. In folk medicine, preparations from porcini mushroom, fungus, some tinder fungus and other species are used.

The list of official preparations contains numerous preparations from mushrooms:

• substances extracted from the culture medium of penicillium and other fungi (used in the production of antibiotics).

Use for hallucinogenic purposes

Some types of mushrooms contain psychoactive substances and have a hallucinogenic effect, so ancient peoples used them in various rituals and initiations; in particular, fly agaric mushrooms were used by the shamans of some peoples of Siberia.

Use as pesticides

Preparations based on micromycetes.

Many fungi are capable of interacting with other organisms through their metabolites, or by directly infecting them. The use of agricultural pesticides from some of these fungi is being considered as an opportunity to control pest population sizes agriculture, such as insect pests, nematodes, or other fungi that damage plants. For example, entomopathogenic fungi are used as biopesticides (for example, the drug Boverin from Beauveria bassiana, other drugs from Metarhizium anisopliae, Hirsutella, Paecilomyces fumosoroseus And Verticillium lecanii (=Lecanicillium lecanii). Fly agaric has long been used as an insecticide.

Technical Application

The production of citric acid based on biotechnology - microbiological synthesis - has become widespread.

Damage to the farm

Known large number various pathogenic fungi that cause diseases of plants (up to 1/3 of the growing crop and during storage are lost annually due to their fault), animals and humans (dermatoses, diseases of the hair, nails, respiratory and genital tract, and oral cavity). They cause severe food poisoning. Wood-destroying fungi cause rapid destruction of wood materials, buildings and products, and therefore are considered pathogenic in forest phytopathology.

Literature

• "Funghi", - Instituto Geografico De Agostini, Novara, Italy, 1997
• Bondartseva M.A. Key to mushrooms of Russia. Order Aphyllophoraceae. St. Petersburg: Nauka, 1998. Vol. 2
• Garibova L.V., Sidorova I. I. Mushrooms. Encyclopedia of Russian nature. - M.: 1999
• Garibova L.V., Lekomtseva S.N. Fundamentals of mycology (morphology and taxonomy of fungi and fungi-like organisms). M.: KMK, 2007
• Gorlenko M.V. etc. Mushrooms of the USSR. - M.: 1980
• Dyakov Yu., Shnyreva A., Sergeev A. Introduction to fungal genetics. M.: Academy, 2005
• World of plants. in 7 volumes / Ed. A.L. Takhtajyan(chief ed.) and others. T. 2. Mushrooms. / Ed. M.V. Gorlenko. 2nd ed., revised. - M.: Education, 1991. - 475 pp., 24 sheets: ill. - ISBN 5-09-002851-9
• Tobias A. Morphology and reproduction of fungi. M.: Academy, 2006
• Fedorov F.V., Mushrooms. - M., Rosagropromizdat
• Cherepanova N.P. Taxonomy of fungi. - St. Petersburg: SSU Publishing House, 2005

Most characteristic feature Any living organism is its development cycle. Knowledge of the development cycle of fungi is extremely important both for general biological purposes (for correct understanding species boundaries, to clarify the evolution of these organisms), and from a practical point of view. An accurate understanding of the development cycle of fungal pathogens that cause diseases in plants, humans and animals allows us to correctly and effectively combat these pathogens.

Reproduction is the basic property of any living organism. It is the features of reproduction, both sexual and asexual, that are used to determine the taxonomic position of fungi and to establish family relationships between their individual groups. There are three types of reproduction in fungi - vegetative, asexual and sexual.

Vegetative propagation this is the ability of a fungus to reproduce by fragments of the vegetative body, i.e., parts of the mycelium. In a multicellular mycelium, any part of the mycelium containing a cell gives rise to new mycelium. Areas of non-cellular mycelium are also capable of regeneration. Vegetative propagation is also carried out using various modifications of the mycelium. For example, oidia, chlamydospores, and bud cells can be considered as different methods of vegetative propagation.

Asexual reproduction carried out by specialized spores that develop in one way or another, either on the mycelium or from spore-forming cells and form a new individual. Spores of asexual reproduction serve for the mass dispersal of fungi during the growing season.

Sexual reproduction represents the emergence and development of a new generation from a fertilized cell - a zygote, which arose from the fusion of the contents of two cells that differ in gender. When two dioecious cells, called gametes, merge, the sexual process occurs in two phases. The first phase of the sexual process is the fusion of the protoplasmic contents of two cells, i.e. plasmogamy. After plasmogamy, either immediately or after a certain period of time - in different organisms, in different ways - nuclear fusion occurs, i.e. karyogamy. As a result of the fusion of two cells, a special cell is obtained, within which the contents of both the first and second (male and female) cells are concentrated. After the fusion of two nuclei, a diploid nucleus is obtained, in which a double set of chromosomes is concentrated. Thus, during the sexual process, a transition occurs from the haploid state - with a single set of chromosomes, to the diploid state - with a double set of chromosomes in the population nucleus.

After the formation of a diploid nucleus, in some fungi immediately, and in other cases a little later, the diploid nucleus undergoes division, accompanied by a decrease in the number of chromosomes, i.e. reduction division. As a result of reduction division, haploid cells are subsequently obtained, which differ from diploid ones in having half the number of chromosomes. At the same time, each of these cells contains the contents of two previous haploid cells that participated in the sexual process. A recombination of hereditary properties has occurred, and two cells are no longer identical to the first cells. The sexual process thus contributes to the emergence great variety forms

Sexual reproduction is the highest form of reproduction compared to asexual reproduction, which is a more ancient type of reproduction.