A new generation of mushrooms
Mushrooms reproduce asexually, autonomic and sexually.
1. Vegetative reproduction is carried out by parts of the mycelium. These parts are separated from the total mass, then grow and develop independently. Rain mushrooms multiply by budding. On the cells of the mycelium, outgrowths are formed, which then increase in size, and after they are loosened.
Lower mushrooms are the simplest and most often live in water. Spores of these fungi have flagella and swim well.
2. Asexual reproduction is the propagation of spores. Spores can have single or covered with common envelope flagella or dispense with them.
Place the dispute - sporangium. The Gifa on which it is located is called the sporangiosphere. Disputes with flagella are in zoosporangia. Spores without flagella are called conidia and openly sit on the hyphae-condylar.
Since propagation by spores depends on the will of the case, the fungi release a huge amount of spores to ensure the reproduction of their species. For example, meadow mushroom, whose diameter is 8 cm, reproduces 1.8 billion spores! In a mature state, this fungus emits 40 million spores in one hour. The number of spores in the raincoat totals 5-6 billion!
In general, mushroom spores spread through the air. A light wind can carry them very far. The direction and speed of the wind are random quantities, the same as the precipitation and humidity of the air.
When spores descend to the ground, they form a mycelium, but for its development, suitable soil and a favorable external environment( temperature and humidity) are needed. In order for a fruit body to appear, two spores of different sex must germinate in one place. Only in this case the fruiting body will develop. Its development in large fungi can go in two ways: the first way leads to the appearance of marsupials, the second - basidial.
3. Propagation by spores gives rise to the primary mycelium. The secondary mycelium is formed by the fusion of two primary mycelia. This is sexual reproduction.
The sexual process is the fusion of male and female gametes, as a result of which a zygote is formed. In lower fungi, gametes are mobile, may be the same in size or differ. If gametes are also dissimilar in structure, they are formed in female and male genital organs.
A stationary egg can be fertilized by moving spermatozoa or an outgrowth of antheridia, which overflows its contents in the oogonia. The emerging secondary mycelium grows and feeds and, under favorable conditions, produces fruit bodies.
Fruit bodies accumulate and mature spores.
It is known that any organism receives a hereditary program for further development. If there are convenient conditions for this, the organism realizes it. The whole hereditary program is contained in the nuclei of cells. There are mycelium with a full program or with its half. In the first case, development is normal, and in the second, to form a new diploid organism, it is necessary to merge one haploid halves with the other.
After fusion, there may be two ways of development in fungi.
The first method of development is used if the diploid stage is short-lived, that is, after the sexual process the nuclei merge and divide twice( reduction division).This leads to the formation of haploid structures. Each mushroom is supplied with a part of the hereditary program.
The second method is typical for mushrooms, which after hibernation fall into hibernation. In this case, the zygote is covered with a shell and waits for spring. Then it sprouts, that is, the reduction division takes place and haploid spores begin to develop.
Mushrooms are amazing organisms that have been able to adapt to environmental conditions.
How is the basidial fungus
formed? Ascomycetes
Ascomycetes( marsupial fungi) include stitches, morels and truffles( Fig.).
Fig. Truffles
Their mycelium is distributed in the soil and consists of cells with one core. Hypha cells only merge in a growing fruiting body. Thus a secondary mycelium is formed, which consists of cells with two nuclei. When the nuclei merge, they form bags containing 8 ascospores.
Basidiomycetes
Many common species of fungi belong to basidiomycetes. A feature of these fungi is that in basidiomycetes, the heterozygous hyphae merge before the fruiting body is formed. Therefore, the mycelium that has spread in the soil is secondary. Under favorable conditions, fruit bodies begin to form, which completely consist of cells with two nuclei.
Cells, where both nuclei merge, appear at the ends of the hyphae and are called basidia. These disputes are also carried by the wind. Thus, in Ascomycetes and Basidiomycetes, the life cycle is thus completed.