General characteristics of the kingdom of mushrooms. Structure, nutrition and reproduction of mushrooms

The fruiting bodies of mushrooms produce a huge number of spores. For example, over 16 billion spores ripen on champignon plates in a week; 7x10 12 spores are formed in the fruiting body of the giant puffball. After ripening, the spores fall out of the fruiting body. The spread of spores in most fungi is carried out by air currents - they transport spores tens and hundreds of kilometers. The spread of spores is also facilitated by animals that feed on the fruiting bodies of various cap mushrooms - rodents, ungulates, and among invertebrates - larvae of fungus flies, mollusks (slugs). The dispersal of spores by animals is called zoochory.

Once in suitable conditions, fungal spores germinate, giving rise to hyphae, which quickly grow in length and soon become branched. Mycelium is formed, penetrating the substrate in all directions. Its threads continue to grow, absorbing nutrients throughout their entire surface. At a certain stage of development, the mycelium begins to bear fruit: in some places the hyphae of the mycelium, grown from different spores, unite when they meet; a dense nodule appears at the junction, and from it the fruiting body of the fungus subsequently develops, the growth of which is completely ensured by the mycelium, which supplies water and the necessary nutrients.

Mushroom development diagram: 1 - germinating spore, 2 - mycelium, 3 - fruiting body

The development of fungal fruiting bodies depends on environmental conditions. Temperature and humidity play a decisive role here. Most cap mushrooms bear fruit at average summer temperatures and a fairly high degree of humidity. If the summer is moderately hot and there are frequent but not prolonged rains, the mushroom harvest will be high. In cold, dry or too rainy summers, mushrooms bear fruit poorly, appearing late and in small quantities. The fruiting of mushrooms is also influenced by the conditions of the previous autumn. It has been noticed that the mycelium develops better and accumulates more nutrients necessary for the development of fruiting bodies in warm and humid autumn. It is after such autumn weather that next year we can expect abundant fruiting of mushrooms.

In relation to temperature and humidity, cap mushrooms are divided into groups. The largest of them are mushrooms of moderate temperature and humidity. However, there are mushrooms that can bear fruit at high temperatures and relatively low humidity. These are mushrooms of steppes, semi-deserts and deserts. Many of them are characterized by the ability to maintain their viability even in conditions of prolonged drought. For example, the fleshy large fruiting bodies of the steppe champignon and white umbrella mushroom, which dry out during drought, come to life after rains and even produce completely viable spores. Other mushrooms, on the contrary, belong to the group of cold-resistant forms: winter honey fungus and oyster mushroom, as well as some hygrophorus can bear fruit at temperatures below 0 ° C.

Cap mushrooms react differently to light. For example, a champignon develops equally both in the light and in the dark, forming normal fruiting bodies, but when placed in the dark, the winter honey fungus and scaly foxtail develop ugly fruiting bodies with a strongly elongated stalk and an underdeveloped cap.

Cap mushrooms are also divided into groups in relation to their feeding substrates. The vast majority of cap mushrooms are characterized by a saprophytic mode of nutrition. Among them there are litter saprophytes living on the forest floor and wood-destroying fungi - xylophages that settle on wood. Litter is the top layer of soil in a forest, which includes various remains of dead vegetation - fallen needles and leaves, pieces of bark, twigs, stems and leaves of various forest herbs, etc. All these elements are decomposed mainly by bacteria and fungi living in the soil - litter saprophytes. Using plant residues as a source of nutrition, fungi assimilate them, process them and return them to the soil in the form of simple organic compounds, which become available to other plants. Thus, mushrooms directly enrich the forest soil and actively participate in the general cycle of substances in nature. This is one of the many aspects of the beneficial activity of cap mushrooms.

In turn, cap mushrooms (xylophages) play a dual role in forestry. Many of them settle on the remains of wood, no longer suitable for use for economic purposes, and, as a rule, carry out the final stage of wood decomposition, begun by fungi from other systematic groups, for example, tinder fungi.

Consequently, having completed the decomposition of wood, most cap mushrooms (xylophages) take part in enriching the forest soil in the same way as litter saprophytes, and the beneficial significance of their activity is beyond doubt.

However, in the group of xylophages there are also harmful fungi. This is primarily a mine or cellar mushroom, which is one of the worst destroyers of wood in buildings. Settling on logs and boards in damp, unventilated areas, the fungus destroys the wood and renders it completely unusable. The fungus belongs to the group of especially harmful wood destroyers - house mushrooms. Another cap mushroom - xylophage - scaly sawfoil destroys railway sleepers, roadside poles, bridge piles, etc.

A very interesting and useful group are mycorrhiza-forming mushrooms. The essence of mycorrhiza - a symbiosis of a fungus and a higher plant - was clarified by the Russian scientist F. M. Kamensky (1881), who first discovered that the branches of the mycelium of some mushrooms, when meeting small lateral roots of trees living nearby, entwine them and form more or less less dense cover.

Somewhat later, the German scientist A. Frank proposed calling such a compound mycorrhiza, or fungal root.

There are two types of mycorrhizae - external, or ectotrophic, when the fungus forms a sheath on the surface of the root and sometimes penetrates the cells of the primary cortex to form a Hartig network in them, and internal, or endotrophic, when the fungus penetrates inside the root and forms tangles of hyphae in its cells, bubble-like swellings, tree-like branches, etc. Cap mycorrhizal fungi are characterized by ectotrophic mycorrhiza; their symbionts are many tree and shrub plants.

The essence of mycorrhiza is the exchange of vital substances between the fungus and the higher plant. The plant supplies the fungus with carbohydrates, which it, as a non-chlorophyll organism, cannot synthesize, and receives from the mycelium water with minerals dissolved in it - nitrogen, phosphorus, potassium - in the form of simple compounds available for absorption. It was also found that the fungus and the plant can exchange vitamins and growth substances, which contribute to the growth and development of both symbionts.

Most plants have mycorrhizae. The group of mycorrhizal fungi is also quite large - among the agaric fungi alone there are over 70 species. Most mycorrhizal fungi do not have a narrow specialization in the choice of symbiont; for example, the white mushroom forms mycorrhiza with pine, spruce, birch or oak. However, some mushrooms still prefer to enter into symbiotic relationships only with a certain breed. For example, boletus - with birch, boletus - with aspen, larch buttercup - with larch.

The undoubted benefit of mycorrhiza for fungi and their symbionts is proven, firstly, by the wide distribution of the mycotrophic method of nutrition (i.e., feeding plants with the help of mycorrhizal fungi) in nature, and also by the fact that forest mycorrhizal fungi usually do not live outside the forest and in artificial conditions, do not bear fruit, and, in addition, due to the fact that Without mycorrhiza, many tree species, especially young trees, grow poorly or die.

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Mushroom mycelium

A mycelium is a complex infrastructure on which all the plants in the world are located. In ten cubic centimeters of soil you can find eight kilometers of its webs. The human foot is covered with about half a million kilometers of closely spaced webs. - Paul Stamets, mycologist What's going on in those webs? In the early 1990s, the idea first emerged that the network of these webs not only transferred food and chemicals, but was also a smart and self-learning communication network. Looking at even small sections of this network, it is easy to recognize a familiar structure. Internet graphics look exactly the same. The network branches, and if one of the branches fails, it is quickly replaced by workarounds. Its nodes, located in strategic areas, are better supplied with power due to less active places, and are enlarged. These webs have sensitivity. And each web can transmit information to the entire network. And there is no “central server”. Each web is independent, and the information it collects can be transmitted to the network in all directions. Thus, the basic model of the Internet has existed at all times, only it was hidden in the ground. The network itself seems to be able to grow indefinitely. For example, in Michigan, a mycelium was found that had grown underground over an area of ​​nine square kilometers. It is estimated to be about 2000 years old.

When does a network decide to grow mushrooms?

Sometimes the reason is a danger to the future of the network. If the forest feeding the network burns, the mycelium stops receiving sugars from tree roots. Then she germinates mushrooms at her outermost ends so that they spread mushroom spores, “freeing” her genes and giving them the opportunity to find a new place. This is how the expression “mushrooms after the rain” appeared. Rain washes organic rot out of the ground and, in essence, deprives the network of its source of nutrition - then the network sends “rescue teams” with spores in search of a new refuge.

“Searching for a new home” is another thing that distinguishes mushrooms from the animal and plant kingdoms. There are fungi that spread their spores much like fruits spread their seeds. Others produce pheromones that cause living things to compulsively crave them. Collectors of white truffles use them to search for pigs, as the smell of these mushrooms is similar to the smell of alpha boar. However, there are more complex and cruel ways of spreading mushrooms. Observations of West African ants of the species Megaloponera foetens recorded that they annually climb tall trees and plunge their jaws into the trunk with such force that after this they cannot free themselves and die. Previously, cases of mass suicide of ants have not been observed.

It turned out that the insects act against their will, and someone else sends them to their death. The reason is the smallest spores of the fungus, which sometimes manage to get into the mouths of ants. Once in the insect's head, the spore sends chemicals to its brain. After this, the ant begins to climb the nearest tree and sinks its jaws into its bark. Here, as if waking up from a nightmare, he begins to try to free himself and, in the end, exhausted, he dies. After about two weeks, mushrooms sprout from his head.

On trees in Cameroon you can see hundreds of mushrooms growing from the bodies of ants. For fungi, this power over the brain is a means of reproduction: they use the ant's legs to climb a tree, and the height helps the wind disperse their spores; this is how they find new homes and... new ants. The Thai "zombie mushroom" Ophiocordyceps unilateralis encourages the ants that feed on it to climb the leaves of some plants. The distance that infected ants travel for this purpose significantly exceeds the distances in their normal life, and therefore, having reached the leaves, the insects die of fatigue and hunger, and two weeks later mushrooms sprout from their bodies.

These mushrooms are perhaps the most amazing creatures, as they produce chemicals similar to LSD, but we have yet to find a drug that causes behavior that suits someone's interests. And Professor David Hughes discovered fungi that control the brains of spiders, lice and flies. This is not a coincidence, natural selection, or a side effect of another process. These insects are sent against their will to places where they shouldn’t be, but the mushrooms like them. When the researchers transferred the infected ants to other leaves, the mushrooms simply did not germinate....

Many people believe that mushrooms are a special type of plant, but in fact, mushrooms are not plants. Until the mid-20th century, scientists actually classified them as plants, but then studies were done that showed that it was completely unlawful to classify these organisms as plants.

At the moment, taxonomists distinguish fungi into a separate independent kingdom of living nature along with plants, animals and bacteria. Previously, they belonged to lower spore plants and, in the old scientific understanding, were considered chlorophyll-free lower plants. Now there are about 100 thousand species of mushrooms.

Mushrooms are not able to absorb carbon dioxide from the air and feed on ready-made organic matter found in the soil. Fungi differ from plants in a number of very significant ways. Their cells lack the pigment chlorophyll, which is found only in green plants and some bacteria, and thanks to it, plants are able to independently produce organic substances from carbon dioxide contained in the air and water, which they absorb with the help of their roots. Fungi are not capable of photosynthesis, and they, accordingly, are not able to produce organic substances on their own. This is one of the most important characteristics that distinguishes them from plants.

Similarities between mushrooms and animals

Despite the fact that these organisms do not outwardly resemble animals in any way and, it would seem, there can be nothing in common between them, however, this is not so. There are a small number of similarities between fungi and animals. For example, mushrooms, like animals, feed only on ready-made organic substances that are produced by other living organisms, mainly plants. Among other things, fungal cells contain a special substance - a polysaccharide called chitin. In addition to fungi, chitin has also been found in animal cells; in particular, it is part of the integument of insects.

Similarities between mushrooms and plants

Fungi are similar to plants by the fact that the growth of these organisms continues throughout their life. No matter how long the mushroom, that is, its mycelium, exists, it will grow and increase in size throughout this time. The same thing happens in plants. Even a thousand-year-old oak tree gives a small, but still, increase every year. And the plant's root system will also grow continuously throughout its life.

Many people believe that mushrooms, although a tasty dish, are completely useless in nutritional terms, however, this is a misconception. The mushrooms that we use for food contain some amount of protein, in addition, they contain amino acids that our body needs. And, most importantly, it contains a certain amount of vitamins that our body cannot synthesize on its own.

Varieties and propagation of mushrooms

You and I are accustomed to seeing mushrooms, such as boletus, boletus, toadstool, fly agaric, and we believe that this is a whole organism, however, this is not so. The main part of the fungus is located underground or in a tree trunk and is hidden from our eyes. The mushroom is a mycelium or mycelium, which consists of very thin threads called “fungal hyphae”. But what we see on the surface is usually a fruiting body, that is, this is the part of a living organism that serves for reproduction - the spread of spores.

Fungi spread by spores, and not by seeds, like plants. The same mycelium that is located either in the soil or in the trunk of a rotting tree performs the very important function of decomposing organic remains. That is why fungi belong to the group of decomposers, that is, organisms capable of returning organic matter to a state accessible to the root system of plants. If it were not for mushrooms, our forests would be filled with leaves, twigs, and other remains that die every year.

Fungi are a very large group of organisms. This includes not only those mushrooms that we are used to picking in the forest, or those that are accessible to our eyes. These are various edible and non-edible mushrooms, tinder fungi. These also include mold (mold fungus) - this is exactly the mold that can be found on cheese, on bread, and anywhere else.

The kingdom of fungi also includes organisms such as yeast. This is the same yeast that is used in baking and in the production of various alcoholic beverages, that is, in processes associated with fermentation.

Fungi are also found in organisms such as lichens. Lichen is a symbiotic organism, that is, it includes representatives of two different kingdoms - the kingdom of fungi and the kingdom of plants. This is the mutual cohabitation of a fungus and algae. Among the lichens there are also those that are used in medicine, for example moss, or reindeer moss, which grows in our pine forests and is a snow-white cover on the soil. If the year is dry and the summer is dry, then moss crunches underfoot, but during the wet period it is soft and it is very clearly noticeable that it actually contains a mushroom.

MUSHROOMS
a group of spore-bearing organisms classified in a special kingdom of life, sometimes resembling plants in appearance, but lacking the green pigment chlorophyll, true roots, stems and leaves. Spores, like seeds, disperse and germinate into new organisms, but do not contain an embryo and usually consist of a single cell. Currently, it is believed that at least 1.5 million species of fungi live on the globe, but only 70,000 of them have been described, i.e. less than 5%. This group usually includes the so-called. slime molds, molds commonly found on decaying plants and soil, yeasts well known for their role in the production of alcoholic beverages and other foods, cap fungi, and the causative agents of many crop diseases such as smut, rust and mildew. The importance of mushrooms in nature and in human life cannot be overestimated. First of all, this is the so-called. decomposers necessary for the decomposition of organic substances, including cellulose and lignin, i.e. for the global cycle of elements. Mushrooms, primarily many of their cap types, are eaten, and some of them are among the most expensive delicacies (truffles). They also provide the "food of the future" - edible protein (mycoprotein). Fungi are increasingly used for biological control of harmful insects and nematodes, replacing pesticides. They form a symbiotic association - mycorrhiza - with plant roots, which improves the growth of the latter and allows trees to settle on almost barren soil. Advances in genetic engineering have made yeast real living factories for the large-scale production of complex compounds, in particular antibiotics and hormones needed in medicine and enzymes used in industry. On the other hand, fungi, settling in the tissues of plants and animals, cause dangerous diseases (phytomycosis, mycoses); In addition, they form toxic mycotoxins that cause food poisoning and often lead to spoilage of a wide variety of useful materials.

FUNGAL PLANT DISEASES are dangerous for many food crops, often leading to significant crop losses and huge losses for agriculture. The rust fungus forms dense growths on the underside of blackberry leaves, penetrates plant leaves through stomata in the epidermis and grows inside the leaf, releasing branching sporangiophores. Sporangia develop at their ends, which then fall off and are carried by wind or raindrops to other plants. There they germinate or form flagellated spores, which give rise to new fungi.

HAT MUSHROOM - is a so-called. a fruiting body growing from mycelium (mycelium) - branched thread-like structures of whitish color (hyphae) growing in the top layer of soil or in the thickness of the litter. Spores form in the fruiting body. Its growth begins with the formation of a compact mass of hyphae on the mycelium, which outwardly resembles a bud. In some species (for example, poisonous fly agarics), the outer membranous covering is differentiated in this “bud”. Over time, it breaks, releasing a vertical leg with a cap, and it itself remains at the base of the leg in the form of a so-called. vagina. The underside of the cap is initially covered with a blanket, which eventually also breaks, forming a ring on the stem and revealing the spore-bearing plates or tubes. The first to ripen are spores along the periphery of the cap. As they fall off, its edge softens and rots. The process proceeds centrifugally, and when all the spores are scattered, soon there is nothing left of the cap either.

Fungi are a separate kingdom of organisms. There are about 100 thousand species of mushrooms on the planet. Their vegetative body is called mycelium (from the gr. Mikos - mushroom), or mycelium. Some fungi have a body consisting of a single cell (or even non-cellular), others - from many cells.

The mycelium of a multicellular fungus is formed by thread-like hyphae, the close interlacing of hyphae above the soil surface forms a fruiting body, often in the form of a cap (russula, honey mushrooms, fly agarics, porcini mushroom, boletus, etc.). Fungal cells contain one or more nuclei and never contain chlorophyll. Therefore, fungi are not capable of photosynthesis and feed on ready-made organic substances.

Many types of fungi enter into mutually beneficial cohabitation with higher plants and algae (they form lichens). In fungal cells there is a vacuole with cell sap; they store glycogen (a substance similar to starch) and oils.

The cell membrane of fungi consists of various substances, in particular chitin, and less commonly cellulose. Chitin enhances the strength and resistance of the cell membrane to various chemicals.

Fungi reproduce by sexual, asexual and vegetative methods. Vegetative reproduction occurs by pieces of mycelium, budding, etc. During non-sexual reproduction, spores are formed in sporangia, on the surface of conidia. During sexual reproduction of higher fungi, ascospores and basidiospores are formed.

Higher fungi have multicellular branched mycelium; only yeast have microscopic unicellular mycelium; when budding, they form chains of cells that crumble into individual cells. They live on the surface of plants in various sugary liquids. This property is used in baking, brewing, etc.

Penicillium- one of the molds, has a mycelium divided by partitions into individual cells. It is found on food products in the form of green or blue films. Spores are formed on conidia located above the substrate and look like brushes. Antibiotics are obtained from these mushrooms and are used in medicine.

With a cap, mushrooms form a fruiting body in the form of a cap - this is a dense interweaving of hyphae. The top of the cap is covered with skin, often of bright colors. At the bottom of the cap there is a special layer where spores develop - it comes in the form of plates (russula, champignons, honey mushrooms, fly agarics) and a sieve made up of tubes (ceps, boletus).

Often mushrooms enter into symbiosis (beneficial to both communities) with plant roots, forming mycorrhiza, or mycorrhiza. This is reflected in the names of some mushrooms: boletus, boletus. Among the cap mushrooms there are many edible mushrooms - porcini mushroom, butterfly, champignon, milk mushroom, honey mushroom, chanterelle, russula, but there are also poisonous, even deadly poisonous - toadstool, fly agarics, sulfur-yellow false honey fungus and some others.