Description of higher and lower mushrooms. General characteristics Higher fungi include

All fungi are divided into lower fungi and higher fungi.

lower mushrooms , the vegetative body of which is formed by the mycelium of the cellular structure, have a less perfect sexual method of reproduction than higher mushrooms, they have a highly branched, non-septate (with no partitions), multi-core mycelium. Lower fungi are unicellular fungi. These mushrooms include the well-known white mold or mukor mushroom. Despite the fact that outwardly mucor looks like a multicellular organism, in fact it is all one cell, which has grown in one cytoplasm with a huge number of nuclei. The elongated filaments are called mycelium. The expansion at the ends of the mycelium has black heads (sporangia), in which spores are formed, with the help of which the fungus reproduces.

The main difference between the lower and higher fungi is the structure of the mycelium. Non-cellular mycelium in lower fungi, while in higher ones it is cellular or articulated. The mycelium of lower fungi lives no more than five days. Lower fungi reproduce asexually. Mukor also has the ability to reproduce also by dividing the mycelium.

The life span of the mycelium of higher fungi can be several years. Higher fungi can reproduce sexually, asexually and vegetatively. When we talk about the vegetative method, we mean the breakdown of hyphae into individual cells. Asexual reproduction occurs through spores. Sexual reproduction has several ways: the connection of haploid cells, somatogamy and the method of spermatization.

The vegetative phase in lower fungi consists of plasmodium (a multinuclear mobile protoplasmic mass devoid of cell walls) or pseudoplasmodium (an aggregate of naked mononuclear amoeboid cells that retain their individuality). Nutrition is both holozoic and absorptive. Flagellar cells, when present, usually bear two unequal flagella. Spores and sporangia (spore receptacles) are usually numerous. Includes one section (type) slimy fungi, or myxomycetes.

In higher fungi, plasmodium or pseudoplasmodium is absent. The vegetative phase consists of filaments (hyphae) or cells with a distinct cell wall. Food is only absorption. Flagellar cells, when present, with one or two flagella. Includes departments: mastigomycetes, or zoosporous fungi (Mastigomycota), zygomycetes (Zygomycota), ascomycetes (Ascomycota) and basidiomycetes (Basidiomycota), as well as an artificial department of imperfect fungi (Deuteromycota).

Mushrooms are mysterious organisms. Suffice it to say that the question of the place of fungi in the system of the organic world is still being discussed.

It is probably fair to single them out as a special kingdom of nature along with the kingdoms of animals, plants, and perhaps prokaryotes (organisms without a real nucleus). The above is all the more likely that fungi have features of animal and plant organization. By the nature of nitrogen metabolism, the presence of chitin in the cell membrane, the reserve product of glycogen, and not starch, they approach animals. At the same time, according to the method of nutrition by absorption, and not ingestion of food, unlimited growth, they resemble plants.

First, the author gives general information about fungi, the features of their reproduction and metabolism. He expressed an interesting idea about the relic nature of some aspects of the exchange in fungi. In some cases, this may be true. In fact, it is difficult to explain the need for fungi of such compounds as phalloidinx and amanitin of the pale toadstool or muscarine of the red fly agaric and a number of others that are toxic to the animal organism and harmless to the fungi themselves. It can be assumed that these are the remains of some metabolic products that were necessary for fungi. Probably, the same kind of substances include the toxins of some Fusariums, which are the cause of serious human diseases (drunken bread, septic tonsillitis, etc.). Therefore, the assumptions of A. A. Titaev about the nature of metabolism in fungi, although controversial, make us think and work in this direction.

The author's considerations about the influence of terrestrial magnetism on the nature of the growth of the fruiting bodies of mushrooms in the forest are peculiar. In his opinion, some of them are characterized by the arrangement in rows in the direction from north to south under the influence of the forces of terrestrial magnetism. The author confirms his ideas with experiments, which, it seems to us, indicate only the possibility of such a phenomenon, but do not prove it, since they are not enough, and the methodology for their formulation needs to be improved. Such experiments are of interest only as starting points for further research.

It is known that mushrooms in the forest are located not only in rows, but also in large dense groups on a substrate characteristic of them (for example, summer mushroom, autumn mushroom, brick-red mushroom, etc.). An important role in the placement of fruiting bodies in the forest is played by the nature of lighting. Some mushrooms are found more often on the edges, clearings, others, on the contrary, under the forest canopy, etc. In a word, if terrestrial magnetism plays some role in the nature of the distribution of mushrooms in the forest, then this is only one of the factors, far from being the main one.

A special section is devoted to unusual forms of mushrooms. For example, funnel talker resembles the shape of a vase. Everything written here is interesting. However, it should be noted that the classification of anomalies in fungi is most fully presented in the book "Fundamentals of Mycology" by A. A. Yachevsky, published in 1933 (pp. 844-851). There are also data on the phenomenon of cap fusion, which interested the author so much. Probably, in most cases, fusion occurs even when the fruiting bodies are laid (something similar to Siamese twins is obtained), and not after the caps have appeared on the surface. Therefore, naturally, the author's attempts to grow together the caps of adult mushrooms practically do not give the desired result.

A list of cap mushrooms found by A. A. Titaev in the Moscow region is given. This list is of certain importance for the knowledge of the flora of the higher fungi of the Moscow region.

Thus, some interesting data on the biology of higher fungi are collected. A number of the author's provisions are debatable and insufficiently proven. However, the value of any work is not only in the fact that it reports a certain amount of facts, but also in how much it awakens thought and makes you experiment in the direction outlined by the author. To a certain extent, this is what makes A. A. Titaev's book interesting.

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Src="https://present5.com/presentation/1/34811856_442531718.pdf-img/34811856_442531718.pdf-1.jpg" alt="(!LANG:>Classification of the fungi kingdom Inferior and superior fungi">!}

Src="https://present5.com/presentation/1/34811856_442531718.pdf-img/34811856_442531718.pdf-2.jpg" alt="(!LANG:> LOWER FUNGI"> НИЗШИЕ ГРИБЫ Ни зшие грибы Характеризуются неклеточным, не имеющим перегородок мицелием (грибницей); у наиболее примитивно организованных хитридиомицетов вегетативное тело представляет собой голый протопласт. Иногда гифы грибов не образуются, а возникает плазмодий- разрастание цитоплазмы со многими ядрами. В связи с пересмотром состава царства грибов в эту группу в разное время входили входят: Миксомицеты (Myxomycota) Оомицеты(Oomycota) Гломеромицеты(Glomeromycota) Гифохитриомицеты(Hyphochytriomycota) Лабиринтуломицеты(Labyrinthulomycota) Хитридиомицеты(Chytridiomycota) Зигомицеты(Zygomycota)!}

Src="https://present5.com/presentation/1/34811856_442531718.pdf-img/34811856_442531718.pdf-4.jpg" alt="(!LANG:> Haploid syncytium (sometimes with a small amount of Zygomycota"> Гаплоидный синцитий (иногда с небольшим Зигомицеты (Zygomycota количеством перегородок), у наиболее примитивных в виде голого комочка протоплазмы - амёбоида или в виде одной клетки с ризоидами, помимо хитина в клеточной стенке много пектина, способность к почкованию, бесполое размножение спорангиоспорами, зигогамия. Отдел грибов, объединяющий 10 порядков, 27 семейств, около 170 родов и более 1000 видов. Отличаются развитым ценоцитным мицелием непостоянной толщины, в котором септы образуются только для отделения репродуктивных органов. Почти все представители этого отдела одноклеточные ведущие наземный образ жизни. Му коровые: Обычно это быстро растущие грибы. На их широкой гифе нет септы. Гифа растёт главным образом внутри субстрата. Множество видов портят пищу. Другие могут вызывать микозы.!}

Src="https://present5.com/presentation/1/34811856_442531718.pdf-img/34811856_442531718.pdf-6.jpg" alt="(!LANG:>Ascomycetes (from Greek ἀσκός - bag), or marsupials (lat. Ascomycota) mushroom in the picture"> Аскомицеты (от греч. ἀσκός - сумка), или сумчатые грибы (лат. Ascomycota) на рисунке гриб сморчёк конический!}

Src="https://present5.com/presentation/1/34811856_442531718.pdf-img/34811856_442531718.pdf-7.jpg" alt="(!LANG:>The sexual process in Ascomycetes The main feature of Ascomycetes is"> Половой процесс у аскомицетов Основной признак аскомицетов - образование в результате полового процесса сумок (или асков) - одноклеточных структур, содержащих фиксированное число аскоспор, обычно 8. Сумки образуются или непосредственно из зиготы (у низших аскомицетов), или на развивающихся из зиготы аскогенных гифах. В сумке происходит слияние ядер зиготы, а затем мейотическое деление диплоидного ядра и образование гаплоидных аскоспор. У высших аскомицетов сумка представляет не только место образования аскоспор, но и активно участвует в их распространении.!}

Src="https://present5.com/presentation/1/34811856_442531718.pdf-img/34811856_442531718.pdf-8.jpg" alt="(!LANG:>Part of ascomycete hyphae with septa Ascomycete vegetative body -"> Часть гифы аскомицетов с септой Вегетативное тело аскомицетов - разветвленный гаплоидный мицелий, состоящий из многоядерных или одноядерных клеток. В отличие от зигомицетов перегородки (септы) в мицелии аскомицетов образуются упорядоченно, синхронно с делением ядер. Развитие септ происходит от стенок гифы к центру, напоминая сужение диафрагмы в объективе фотоаппарата. В центре септы остается пора (рис. 51), через которую происходит движение цитоплазмы с со скоростью от 1- 2 до 25- 40 см/ч. Некоторые органеллы клетки, даже ядра, могут мигрировать через поры. Наличие пор в септах играет существенную роль в переносе питательных веществ по гифам в зону роста.!}

Src="https://present5.com/presentation/1/34811856_442531718.pdf-img/34811856_442531718.pdf-9.jpg" alt="(!LANG:>Yeast life cycle Ascomycete yeast budding is holoblastic:"> Жизненный цикл дрожжей Почкование у аскомицетных дрожжей голобластическое: клеточная стенка материнской клетки размягчается, выгибается наружу и даёт начало клеточной стенке дочерней. Гаплоидные аскомицетные дрожжевые клетки имеют два типа спаривания: a и α. Термин «пол» не используется, поскольку клетки морфологически идентичны и различаются только одним генетическим локусом mat (от англ. mating - спаривание). Клетки разных типов могут сливаться и образовывать диплоид a/α, который после мейоза даёт 4 гаплоидных аскоспоры: две a и две α. Вегетативное размножение аскомицетных дрожжей возможно у разных видов либо только на гаплоидной стадии, либо только на диплоидной, либо на обеих (гапло- диплоидные дрожжи)!}

Src="https://present5.com/presentation/1/34811856_442531718.pdf-img/34811856_442531718.pdf-10.jpg" alt="(!LANG:>Ascomycete fruit bodies There are four types of marsupial fungi"> Плодовые тела аскомицетов У сумчатых грибов имеются четыре типа плодовых тел: Клейстотеции (клейстокарпии) представляют собой полностью замкнутое плодовое тело с находящимися внутри асками, освобождающимися после разрушения его стенок. Перитеции (др. -греч. περι- - возле, около, θήκη - хранилище) - почти замкнуты («полузамкнуты»), то есть сумки окружены перидием, обычно имеют кувшинообразную форму с выводным отверстием в верхней части. Апотеции - открытые вместилища аск. Образуют чаши (блюдца). По верхней стороне плодового тела расположен слой сумок и парафиз; парафизы, пока сумки незрелые, могут смыкаться над ними своими вершинами и выполнять защитную функцию. Также образуют сморщенную поверхность сморчков (причём рёбра складок стерильны), могут, однако, не раскрываться (у трюфелей). .!}

Src="https://present5.com/presentation/1/34811856_442531718.pdf-img/34811856_442531718.pdf-11.jpg" alt="(!LANG:>Cleistothecia stroma">!}

Src="https://present5.com/presentation/1/34811856_442531718.pdf-img/34811856_442531718.pdf-12.jpg" alt="(!LANG:>Stomas with peritecii">!}

Src="https://present5.com/presentation/1/34811856_442531718.pdf-img/34811856_442531718.pdf-13.jpg" alt="(!LANG:>Apothece">!}

Src="https://present5.com/presentation/1/34811856_442531718.pdf-img/34811856_442531718.pdf-14.jpg" alt="(!LANG:> Deuteromycetes Deuteromycetes (lat. Deuteromycota), or Imperfect fungi (lat. ."> Дейтеромицеты Дейтеромицеты (лат. Deuteromycota), или Несовершенные грибы (лат. Fungi imperfecti) - нетаксономическая группа грибов, ранее считавшаяся отделом. Их тело состоит из расчленённых прозрачных или окрашенных многоклеточных гиф и иногда из почкующихся клеток. Размножаются исключительно бесполым путём, при котором образование конидий происходит на изолированных или расположенных группами конидиеносцах или специальных образованиях, называемых пикнидами. К дейтеромицетам относятся три порядка: Sphaeropsidales, Melanconiales и Hyphomycetales (Moniliales), представители которых широко распространены в почве. Грибы порядка Sphaeropsidales характеризуются конидиями, которые образуются в пикнидах, остающихся закрытыми или открывающихся наружу порами или трещинами. Сюда входит род Phoma и др. Виды рода Phoma образуют микоризу с корнями некоторых растений.!}

The body of the fungus is mycelium, made up of fine threads hyphae. The mycelium has a close relationship with the substrate, which is due to the osmotic absorption of nutrients. At higher fungi, the mycelium is divided into individual cells by partitions - septa, i.e. they are septic (cellular) mycelium. Inferior mushrooms have non-cellular structure mycelium, since its hyphae are not divided into partitions, but are, as it were, one branched cell with many nuclei.

Mushrooms are isolated in their morphophysiological organization from the rest of the world of living beings. They cannot be attributed to either plants or animals. There are two theories of the origin of fungi: animal and plant, since fungal cells have signs of both animal and plant cells (Table 5.2).

Plant origin theory fungi suggests their origin from green algae, from which it follows that fungi are primarily a clearly regressive group of plants that have lost chloroplasts.

Animal origin theory is based on the fact that fungi are initially chlorophyll-free organisms, i.e. come from the simplest heterotrophic organisms, and not from algae. This theory is preferable, since chlorophyll-free algae, classified as green, accumulate starch as a reserve product, while fungi do not have starch.

Table 5.2. Features of the structure of the fungal cell

Fungi are heterotrophs. Like bacteria, they are characterized by extracellular digestion, carried out by releasing enzymes into the external environment. The absorption of split nutrients occurs osmotically, the entire surface of the body. Mycelium cells store carbohydrates in the form of glycogen as reserve nutrients, fats in the form of lipid droplets, and proteins in vacuoles.

Mushrooms are capable enter into symbiosis with higher plants, forming mycorrhiza(mushroom root). Mushrooms use carbohydrates synthesized by the plant and extract for it (due to the mineralization of organic compounds) various compounds with nitrogen, phosphorus, produce growth activators and vitamin-like substances.

Multiply fungi can vegetatively, asexually and sexually.

Vegetative reproduction can occur by parts of the mycelium (almost all fungi), by budding (yeast). asexual reproduction occurs due to the formation of zoospores, sporangiospores and conidia.

zoospores are formed in fungi leading an aquatic lifestyle (chitridiomycetes, oomycetes). Their mobility is provided by flagella (there are 1 or 2 of them). They are formed inside unicellular zoosporangia and, when ripe, enter the water. Covered with a shell and germinate into a new individual.

sporangiospores are formed endogenously - inside unicellular sporangia arising on sporangiophorous hyphae. In one sporangium, there can be up to 10 thousand spores, which, when ripe, emerge from the sporangium and are distributed by the wind over considerable distances. Once in favorable conditions, the spore germinates into a new mycelium (for example, in mucor).

conidia are formed exogenously on special hyphae - conidiophores. Conidia form chains, detach and, in a favorable environment, germinate into a new mycelium (for example, in a penicillium).

Sexual reproduction in lower fungi happens:

At the fusion of gametes - gametogamy(isogamy, heterogamy and oogamy);

With the fusion of two multinuclear specialized genital organs (gametangia) - zygogamy.

Sexual reproduction in higher fungi:

gametangiogamy; archicarp - female gametangy, antheridium - male (in marsupials);

somatogamy- fusion of haploid somatic cells of heterothallic hyphae (+ and - physiologically different hyphae), for example, in higher basidiomycetes.

The sexual process always ends with the formation of a diploid zygote, its meiotic division and sporulation.

The lower fungi include the department of zygomycote, the higher - departments: marsupials, basidiomycotes, imperfect.

DEPARTMENT OF ZYGOMICOTS(ZYGOMYCOTA)

Mukor is widely distributed in nature as a white mold (Fig. 5.15). Saprophyte according to the method of nutrition; develops on the soil, food products. Mycelial hyphae are an elongated, overgrown giant cell with many nuclei (non-cellular structure). Nuclei - with a haploid set of chromosomes (n). Numerous vertical sporangiophores with brown-black sporangia develop on the mycelium. As a result of mitosis, the contents of the sporangium breaks up into many spores (up to 10 thousand). After maturation, the sporangium shell bursts, and the spores disperse, germinating into new individuals. Reproduction can be asexual (spores), vegetative (mycelium parts), rarely - sexual (zygogamy).

With zygogamy (Fig. 5.16), physiologically different hyphae - heterothallic, conventionally designated as + and -, begin to grow towards each other. At the ends of the hyphae, gametangia are formed, separated by septa from the rest of the hyphae. Next, gametangiogamy occurs, consisting in the fusion of 2 specialized sexual structures (gametangia), not differentiated into gametes, and a zygote with many diploid nuclei is formed. The zygote is covered with a thick brown membrane. After a dormant period, the nuclei undergo meiosis, and the zygote germinates into the germinal sporangium. The haploid nuclei + and - formed after meiosis pass into it. Spores are formed in the sporangium, after their maturation, the sporangium opens, the spores disperse and germinate into new mycelia (+ and -).

Rice. 5.15. The structure of the mucor (Mucor mucedo): 1 - hyphae; 2 - mycelium; 3 - sporangiophore; 4 - sporangium with spores

Some mucor fungi cause mycosis (mucormycosis) of the lungs (false tuberculosis), brain and other human organs, as well as agricultural plants. Many species of the genus have high enzymatic activity, which is used in the production of "soy cheese" from soy seeds, alcohol from potato tubers, etc.

Rice. 5.16. The life cycle of mucor (Mycor): A - haploid phase; B - diploid phase: 1 - two heterothallic (opposite in physiological sign) mycelia; 2 - sporangiophore; 3 - sporangium; 4 - disputes; 5 - spore germination; 6 - gametangy; 7 - pendants; 8 - zygospore; 9 - germinating zygospore; 10 - sprouting mycelium

DEPARTMENT MASSUPULATE MUSHROOMS, OR ASCOMICOTS(ASCOMYCOTA)

This is one of the most extensive classes of fungi, including more than 30 thousand species. This class includes yeast, represented by single budding cells, and fungi with large fruiting bodies, such as morels and stitches. Ascomycots are widely distributed in nature in all natural zones. According to the method of nutrition, they are saprophytes. The mycelium of marsupial fungi is septate, i.e. divided into cells (with a haploid set of chromosomes). A characteristic feature of ascomycot is the presence of bags (ascus) formed as a result of the sexual process. Bags are closed structures containing a certain number of ascospores (spores of sexual reproduction) and are formed as a result of meiosis.

In many ascomycota, bursae form in the fruiting bodies. (subclass fruit marsupials). There are 3 types of fruiting bodies: cleistothecium, perithecium and apothecia. In other representatives, the bags lie open on the mycelium (subclass Voice-marsupials).

Asexual reproduction also plays an important role in the development cycle. Spores of asexual reproduction - conidia- are formed as a result of mitosis on mycelium with haploid nuclei (n) or conidiophores of various structures.

The most common and practical is genus Yeast (Saccharomyces). Yeasts are represented by single, oval cells (Fig. 5.17). Yeasts are characterized by vegetative reproduction, carried out by budding; for this they need a nutrient medium, the presence of sugar in it and a certain temperature. Under unfavorable conditions, sexual process; when 2 haploid daughter cells merge (chologamy), a zygote is formed, which turns into a bag. As a result of meiosis, four spores (ascospores) are formed in the bag, germinating into new yeast cells.

Baker's yeast (Saccharomyces cerevisiae) unite many yeasts bred in culture: alcohol, beer, wine, bakery. All these yeasts decompose sugar into ethyl alcohol and CO 2 . So, when yeast is added to the dough, they begin to decompose the glucose present there, which is formed from starch. In this case, CO 2 is released, which provides the test with porosity and an increase in volume. When baking, ethanol and CO 2 evaporate.

Rice. 5.17. Brewer's yeast (Saccharomyces cerevisiae): A - unicellular thallus; B - bag with ascospores; B - budding

Yeast is a valuable food and feed product. Contain up to 50% protein, as well as fats and carbohydrates. Vitamins are synthesized in large quantities, especially B 2 . They are used in the treatment of anemia, as well as a source of protein when added to feed products in livestock and poultry.

Subclass Fruit marsupials(Carpoascomycetidae)

Representatives of this subclass are characterized by the presence of fruiting bodies in which bags are located. Fruiting bodies are formed by a dense plexus of haploid and dicarionic (binuclear) hyphae, also called ascogenous. Fruiting bodies (ascocarps) are of 3 types: closed (closed) - cleistothecia, semi-closed - perithecia, open (open) - apothecia.

The ergot development cycle proceeds with a change in nuclear phases (Fig. 5.18). So, in the autumn on cereal plants are formed sclerotia- dark purple outside and white inside horns, representing the mycelium of the fungus (dehydrated hyphae) at rest. For the winter, sclerotia fall out of the grasses onto the soil and hibernate in it. In spring, sclerotia germinate on the soil, forming filamentous outgrowths crowned with heads - stroma. In these stromas, as a result of the sexual process, fruiting bodies - perithecia, filled with long cylindrical bags (asci) containing filamentous ascospores - spores of sexual reproduction (Fig. 5.19). Spore maturation occurs as a result of meiosis during the flowering of cereals. Spores are actively ejected with the help of the wind, fall on the stigma of a flowering cereal and germinate. The resulting mycelium penetrates the ovary of the pistil and destroys it. At the ends of the hyphae of the mycelium, as a result of mitosis, conidia are laced off - spores of asexual reproduction, i.e. conidial sporulation occurs. At the same time, the hyphae of the fungus secrete droplets of a sweet liquid - “honey dew”. Insects transfer conidia to the flowers of neighboring plants and infect them.

Rice. 5.18. Ergot purple (Claviceps purpurea): A - ear of rye with sclerotia (1); B - stroma (2) grown on overwintered sclerotia; B - longitudinal section through the stroma with perithecia; G - longitudinal section through the perithecia (3) with bags; E - bag with thread-like ascospores (4); E - conidial sporulation

Rice. 5.19. Development of a bag with ascospores: A, B - formation of a zygote at the top of the ascogenous hypha; B-E - meiosis and development of the bag with ascospores

Unclosed fruiting bodies - apothecia- meet with such representatives as morels (Morchella), stitches (Gyromitra). This open fruiting body is usually saucer-shaped, goblet-shaped, 0.1 to 10 cm in size, of various colors - from bright orange or red to brown and black. Upper layer (hymenium) contains many bags. Fruiting bodies of mushrooms from this group consist of a sterile stem and a folded or lobed cap (Fig. 5.20).

Morels and stitches are edible mushrooms, but when eating, the stitches must first be boiled and the water drained.

Rice. 5.20. Ascomicota - appearance and fruiting bodies of morels and lines:

A - conical morel (Morchella coinca); B - ordinary line (Gyromitra exculenta); 1 - sections of fruiting bodies

DEPARTMENT OF BASIDIOMYCOTA(BASIDIMYCOTA)

This class includes almost all groups of cap mushrooms, numbering about 30 thousand species. The vegetative body is represented by a jointed mycelium, consisting of jointed hyphae.

Reproduction:vegetative(carried out by parts of the mycelium), asexual(conidia) and sexual.

During the sexual process, special organs of sexual reproduction are not formed. The sexual process proceeds in the form somatogamy(Fig. 5.21). From the germinating haploid basidiospore, the primary mycelium develops, which then turns into a jointed one. Each segment is single-core. Coming Soon hologamy- fusion of end hyphae cells. However, the fusion of the contents of the segments is not accompanied by the fusion of the nuclei. Dikaryons are formed, which then synchronously divide. This is how it is formed secondary dicarionic mycelium.

Rice. 5.21. development of the basidiomycete. Scheme of the development cycle: A - scheme of the development cycle: 1 - basidium; 2 - basidiospore; 3 - primary mycelium; 4 - dicarion mycelium; 5 - fruiting body from dicarionic mycelium; B - development of basidium with basidial spores

On the dicarionic mycelium, a fruiting body is formed, which consists of a hemp and a cap. hymenial layer caps can be lamellar or tubular. In the hymenial layer at the ends of dikaryonic hyphae, 2 nuclear cells form basidia. In their development, basidia are homologous to bags. In the basidium, the sexual process is completed, i.e. dikaryon nuclei fuse to form a diploid nucleus. This unicellular basidium is called holobazidia. The resulting diploid nucleus is divided by meiosis with the formation of 4 haploid nuclei (see Fig. 5.19, A). By this time, four tubular outgrowths are formed in the upper part of the basidium - sterigmas. The resulting nuclei flow into the sterigmata and 4 basidiospores are formed: 2 conditionally with the - sign and 2 with the + sign. Therefore, the primary mycelia growing from them will heterothallic. Basidia are formed directly on hyphae or in fruiting bodies of various shapes, but more often consisting of a cap and a stem. There are 3 phases in the development cycle: haploid(short) are basidiospores, dicarionic(lasts the main part of life) - dicarionic mycelium and diploid(short-term) - a young basidium before the formation of basidiospores.

DEPARTMENT OF DEUTEROMYCOTE(DEUTEROMYCOTA),OR IMPERFECT MUSHROOMS(FUNGI IMPERFECT!)

Deuteromycots, along with bisidiomycots and ascomycots, are the largest group of fungi, uniting 25-30 thousand species. These fungi are asexual forms (anamorphs) that reproduce asexually - conidia. Their life cycle takes place in the haploid stage without a sexual process. It is quite possible that deuteromycotes are the most specialized lines of fungal evolution.

It is of great medical importance genus Penicillium. Penicillium has a greenish articulated mycelium, consisting of mononuclear segments. Hyphaconidiophores extending upwards branch at the upper end on sterigmas. The latter in appearance resemble a brush or hand and end with a chain of external spores - conidia (Fig. 5.22). conidia are spores of asexual reproduction produced by mitosis.

A sexual process is also observed, as a result of which closed spherical fruiting bodies of a bright yellow color are formed directly on the mycelium - cleistothecia. Bags with 8 ascospores are formed inside the cleistothecia. Mature ascospores emerge from the sacs after the cleistothecium ruptures.

Penicillium (Penicillium) saprophyte according to the method of nutrition, settling on food products and products (fabrics, leather), causes their deterioration. Penicillium is used not only in medical practice, but also in the food industry for the preparation of special varieties of cheese ("Roquefort").

Rice. 5.22. Deuteromycota (Deuteromycota) penicillium: 1 - mycelium; 2 - conidiophore; 3 - conidia; 4 - sterigmas

The importance of mushrooms in human activity is great. They participate in the cycle of substances in nature. Fungi, like bacteria, mineralize organic matter and take part in the formation of humus. They are used in the food industry for the production of alcohol, wine, beer, kvass, in baking, in the production of proteins and vitamins. Mushrooms form organically active substances - antibiotics, enzymes, organic acids, etc.

Mushrooms can cause corrosion of metals, destroy leather, paper, fabrics. Many fungi cause significant harm to humans, animals and plants, causing a number of diseases (mycoses, ringworm, scab), as well as spoiling food and thereby causing various poisonings.

DEPARTMENT OF LICHEN(LICHENES)

This is a group of symbiotropic plants, consisting of 2 components - autotrophic algae and heterotrophic fungi. The fungal basis of lichens is formed mainly marsupial mushrooms. The algal component consists of species that in most cases are attributed to representatives of the departments green and blue-green algae. Algae isolated from lichen do not differ from free-living forms. Physiologically, this type of symbiosis is based on intercellular exchange between algae and fungi. The fungus feeds on the carbohydrates of the algae, and the algae receive minerals from the fungi. However, symbiosis with fungi leads to the emergence of a new biological quality, which is expressed in the lichen in its ability to reproduce as a single organism.

The vegetative body of lichens is represented by a thallus that has a different color (gray, greenish, brown-brown, yellow or almost black). Morphologically, there are 3 main types of lichen thallus: scale (crustal), leafy and bushy(Fig. 5.23), but there are also transitional forms. The most low-organized - scale, or cortical, thalli; they have the appearance of powdery, granular, tuberculous plaques, tightly growing together with the substrate and not separating from it without significant damage.

Rice. 5.23. Different types of lichen thalli: A - cortical (graphis - Graphis scripta); B - leafy (xanthoria - Xanthoria); B - bushy (cladonia - Cladonia)

More highly organized lichens have a leafy thallus in the form of plates, scales or rosettes, stuck to the soil or trees with the help of rhizins - analogues of rhizoids, consisting of bundles of fungal hyphae.

The highest organization in their structure is achieved by lichens with a bushy type of thallus, which look like a branched bush (12-15 cm in height) and grow together with the substrate only at the base.

According to the anatomical structure, lichens are homeomeric and heteromeric (Fig. 5.24). The more primitive homeomeric- fungal hyphae and algae are evenly distributed throughout the thickness of the thallus. At heteromeric structure on a transverse section of a lichen from above, you can see the so-called upper bark. It is formed by intertwining and closely interlocking fungal hyphae. Under the bark, fungal hyphae lie more loosely, and between them there are algae cells (gonidial layer). Inside the thallus, a core can be distinguished, consisting of loose fungal hyphae and large voids filled with air. Under it is located the lower bark, which is similar in structure to the upper one. Separate hyphae (rhizins) pass through it from the core, fixing the lichen in the substrate.

Most lichens easily tolerate desiccation. Photosynthesis and nutrition cease at this time, which explains their insignificant annual increase.

reproduction lichens predominantly vegetative, is based on the ability of lichens to regenerate from individual sites. It is carried out by fragmentation (separation of sections of the thallus) or with the help of separate groups of algae cells surrounded by fungal hyphae and different in shape - soredia, isidium and lobules (Fig. 5.25). Soredia- the smallest formations of a rounded shape, including one or more algae cells and surrounded by fungal hyphae. Isidia- tuberculate rod-shaped outgrowths on the upper surface of the thallus.

Rice. 5.24. Anatomical structure of lichen thalli: A - section of homeomeric lichen thallus: 1 - fungal hyphae; 2 - algal component;

B - section of a heteromeric lichen: 1 - upper cortical layer; 2 - gonidial layer; 3 - middle layer with fungal hyphae; 4 - lower cortical layer; 5 - rubbers

Rice. 5.25. Reproduction of lichens: A - soredia; B - isidia

Lobules have the form of small scales located vertically on the surface of the thallus or along its edges. In addition, asexual reproduction is observed with the help of spores that are independently formed in both algae and fungi.

sexual reproduction insufficiently studied, but in general proceeds in the same way as in free-living fungi.

Meaning lichens are large. They decompose and mineralize soil organic matter. They are pioneers - one of the first to populate the rocks, they destroy their surface layer and, dying, form humus, on which other plants settle. Lichens are indicators of air purity, as they cannot tolerate even the slightest admixture of sulfur dioxide. From some of their species, paint and a special substance - litmus (for the chemical industry) are obtained. In the tundra and forest-tundra, lichens (moss) are the main food for deer. There are also edible lichens in the semi-desert and desert regions of Kyrgyzstan and Turkmenistan.

Fungi are chlorophyll-free, multicellular or unicellular organisms that feed heterotrophically. Mushrooms are classified into lower and higher mushrooms.

lower mushrooms- unicellular. This includes the well-known white mold, or mukor mushroom. This mushroom often appears on bread, vegetables in the form of a fluffy white coating, which turns black after a while.

The mucor mycelium consists of thin, colorless threads, although it is just one highly expanded cell with many nuclei in the cytoplasm. Mucor reproduces by spores. Some threads of mycelium ( mycelium) rise up and expand at the ends in the form of black heads. Here spores are formed, which, after maturation, crumble and are carried by the wind.

Settling on food products, mucor causes their spoilage. In nature, mucor plays a positive role, decomposing the remains of dead organisms.

Penicillium settles on food and on the soil. Its mycelium consists of branching filaments, separated by partitions into individual cells. In this it differs from the mucor fungus. Penicillium spores are not located in the heads, but at the ends of some threads of the mycelium in small tassels.

Penicillium is bred specifically for medicine - penicillin, which is widely used to suppress many pathogenic bacteria, for example, with tonsillitis, inflammation of the middle ear, and pneumonia.

Microscopically small multicellular fungi oval or elongated. Mycelium does not form. They live in a nutritious liquid rich in sugar. They reproduce by budding. First, a small bulge appears on the adult cell, which gradually increases and turns into an independent cell, which soon separates from the mother cell.

Budding yeast cells look like branching chains. In dough, yeast breaks down sugar into alcohol and carbon dioxide. At the same time, the energy necessary for the yeast to live is released. The carbon dioxide bubbles that form in the dough make it light and porous. This process has long been used in bakery, brewing, winemaking and other industries and agriculture (feed yeast). Bread, or brewer's yeast exists only in culture, while wine yeast is also found in nature on various juicy fruits.

Yeast fungi can cause a disease of the mucous membranes - thrush. Thrush can also spread to internal organs.

Fungi penicillium, aspergillus and yeast fungi belong to marsupials, or they are also called ascomycetes, since they form as a result of the sexual process ascospores(from the Greek "askos" - bag, bag and spore).

Ascomycetes also include truffle mushrooms - very valuable edible mushrooms growing in deciduous forests, thickets of shrubs in southern Europe.

The name "smut" is due to the fact that the ear, on which the smut fungus develops, is covered with a huge amount of black spores and resembles a burnt smut.

Tinder fungi, smut and rust fungi cause significant damage to forestry, gardens and parks. The main way to deal with tinder fungi is the sanitary felling of diseased trees and their immediate removal. The main methods of combating smut and rust fungi are the breeding of resistant varieties of cultivated plants, compliance with the rules of agricultural technology, chemical treatment of plants, etc.

A special group of basidiomycete fungi are hat mushrooms. There are about 8,000 species of them distributed throughout the globe. All of them are saprophytes according to the way of feeding. They got the name "hat" because fruiting bodies are formed on the surface of the mycelium, which look like legs and caps. The mushroom stem is connected to the mycelium, and plates or tubes are placed on the hat on the underside, on which sporulation organs with spores are formed.

The fruit bodies (stalk and cap) of many hat mushrooms are edible, and in some they are poisonous and dangerous to human life.

The most valuable and edible body of the porcini mushroom, it is also called the boletus mushroom. Some mushrooms are known to have medicinal properties. This is a raincoat, porcini mushroom, champignons. They are excellent antiseptics.