Fungi are eukaryotes, so their morphological structure is complex.

Single-celled fungi are divided into yeast-like fungi and yeast-like fungi.

Yeast fungi are round or oval cells without hyphae. They propagate by budding and fall off to form new cells when they mature.

Yeast-like fungus: a chain-like structure formed when cells germinate and mature, and pseudohyphae can reach into the bottom of the culture medium to absorb more nutrients.

The identification method between yeast-like fungi and yeast-like fungi: whether there is mycelium in the cell.

Two: Multicellular fungi

Multicellular fungi are living organisms composed of multiple cells.

Ingredients: spores and hyphae.

When the cell matures, there are "seeds" in it. When the seeds mature, they begin to germinate, break ground and grow upwards, followed by roots, which transport nutrients from underground to all parts of the body.

2. 1 mycelium

Fungi are also similar to the seed reproduction process in nature.

First of all, when the cell matures, there will be spores inside, which will germinate after maturity, further grow into a bud tube, break the wall, and differentiate outside the cell to form hypha, which belongs to conductive tissue like rhizome.

According to the different needs of fungi, different hyphae are differentiated, some of which are responsible for transporting nutrition, called vegetative hyphae, and some are responsible for transporting gas, called aerial hyphae. When the gas content in fungi meets the requirements, aerial hyphae will have no meaning of existence, and it will further differentiate into reproductive hyphae to meet the needs of fungi's continuous reproduction, and many spores can be produced on the reproductive hyphae to prepare for the next' seed germination'.

Hyphae can be divided into septate hyphae and septate hyphae.

Diaphragm hyphae: Diaphragm divides hyphae into multiple cells, and each cell has one or more nuclei.

Diaphragm hypha: The whole hypha is a multinucleated single cell.

2.2 spores

Spores can be divided into sexual spores or asexual spores, and sexual spores are the fusion of sexual organs between cells.

Asexual spores are produced by cell differentiation on reproductive hyphae without cell fusion.

Next, the asexual spores-conidia, scleroderma, budding spores, articular spores and sporangium spores are introduced emphatically.

Conidia are divided into large conidia and small conidia.

Megasporium: the end of reproductive hyphae expands and forms.

Microconidia are formed by cells sprouting from hyphae.

Thick-walled spore: round, because of cytoplasm concentration, cell wall thickening.

Spore: A cell that appears on a reproductive hypha.

Arthrospore: a chain spore formed by the thickening of the cell wall of reproductive hyphae and the appearance of septum.

Sporangium spore: the reproductive hyphae form a saccular structure, and the spores will explode when they mature.

The difference between spores and spores:

Number of spores produced: a cell can only produce one, while spores-a cell can produce multiple.

Location of occurrence: spore intracellular, spore intracellular or extracellular.

Heat resistance: spores have strong heat resistance, and can only be killed in 100℃ 1~3 hours; Spores-poor heat resistance, can be killed in a short time at 60 degrees Celsius.

Generation mechanism: spore-resistance to adverse environment, spore-reproductive body of fungi.

Three: the structure of fungi

Fungi are composed of diaphragm, cell wall, cytoplasm and nucleoli, and some fungi have substances similar to capsules outside the cell wall.

The diaphragm divides a hypha into multiple cells, and the diaphragm of lower fungi is complete. However, with the continuous evolution of fungi adapting to the land environment, holes of different sizes appear, which is convenient for nutrients to flow in cells.

Why did it turn out like this?

The mycelium is equivalent to our hands, and the diaphragm divides the mycelium into several fingers. If one or two cells die due to environmental reasons, it will not affect the function of the whole hand, and you can still reach into the nutrient bottom of the culture medium to get food.

The cell wall of fungi has four layers, which are fiber layer, protein layer, glycoprotein layer and polysaccharide layer from the inside out.

Ok, that's all for today. In this chapter, we mainly study the morphology and structure of fungi.

Microscopically, fungi are similar in shape to tadpoles: a head consisting of one or more round cells, followed by one or more long tails. Of course, some fungi have no tail and only a single cell.

Then, the different components of fungi are introduced respectively. There are spores in the head and many hyphae in the tail.

Spores can be divided into sexual spores and asexual spores. We mainly introduce asexual spores.

There are three kinds of mycelium: aerial mycelium, vegetative mycelium and reproductive mycelium.

Finally, the structure of fungi is introduced, which consists of cell wall, cytoplasm, nucleolus and septum.