Mycorrhizae: what are they and types

Mycorrhiza are the symbiotic and mutualistic associations that are created between the roots of terrestrial plants and certain types of soil fungi . These were discovered in 1885 and attracted the attention of experts for their exceptional and effective relationship to date. So much so, that it is estimated that more than 97% of plant species that exist on the earth’s surface are mycorrhized.

We call mycorrhization the process, natural or artificial, which consists of putting an actively growing root in contact with some type of mycorrhizal fungus. This fusion is carried out through an inoculation process thanks to the use of spores or mycelium.

Nursery mycorrhization

During the mycorrhization process , if it occurs through the induction of the human hand, some key factors for the success of the symbiosis are always taken into account . Among these factors, it is very important to check the age and physiological state of both the plant and the fungus. In addition, it should be avoided that other varieties of fungi are present that may interfere with mycorrhization. Finally, as steps to follow in a natural way, look at the pH of the soil, the water or the available nutrients before continuing with the process.

You should also know that not all plants are compatible or accept the mycorrhization process. Currently, some families of plants are known that are compatible with them, from the cruciferous to the urticaceae, even through the sedge. In addition, great results have been achieved with mycorrhization with legume plants and with citrus fruits.

These are the different types of mycorrhizae :

• Ectomycorrhizae: this type of mycorrhiza is made up of two types of fungi, Basidiomycetes and Ascomycetes. After their union, they develop a thick layer of mycelium just above the cortical zone of the plant’s nutritional roots, forming a kind of network. For this reason, they are also known as the mantle formers. This example of mycorrhiza is very common in forest and woody species.
• Endomycorrhizae: unlike the group before this group of mycorrhizae, they are distinguished because they do not form a fungal mantle in the root of the plant. The fungi that produce them are characterized by intercellularly colonizing the root cortex. In turn, they are divided into three varieties:
• Orchideomycorrhizae: they are those that are linked to the orchid family. These usually form tangles in the root cells of the plant.
• Ericomycorrhizae : linked to the Ericaceae Family, these form a compact structure between the cells of the fungus and the roots.
• Arbuscular mycorrhizae: they are characterized by creating a network of intracellular arbuscules through which the transfer of nutrients will take place.
• Ectendomicorrizas: this type presents a dual colonization of the fungi with the roots. This means that they form both an external and internal cortical mantle in the cortex.

As you have seen so far, mycorrhizae are part of a very interesting symbiosis process. To expand this information, we will mention the main advantages of mycorrhization :

• Mycorrhization improves the assimilation and uptake of nutrients , especially minerals, such as phosphorus, calcium, potassium and even nitrogen and water; both for the plant and for the fungus.
• It influences the improvement of some types of plants, facilitating processes to make them stronger and more resistant to the climate, the type of soil and the presence of substances that acidify the soil, such as sulfur or magnesium.
• Mycorrhization helps protect the plant and the fungus from external pathogens and nematodes that can damage them.
• One of the most important advantages of mycorrhization is that it clearly improves the physiological state and activates the roots . In addition, from the aforementioned, it makes the roots stay active longer, helping with feeding and, therefore, the optimal growth of the plant.
• For its part, the fungus benefits from a greater amount of carbohydrates and vitamins from the plant.

For all the aforementioned, it is not surprising that mycorrhizae are currently used with one of the best tools for gardening, as well as to repopulate deforested areas and improve soils degraded by climate change and the hand of the human being.

To finish, we leave a list of examples of fungi that make mycorrhizae with plant roots:

• Fungi present in ectomycorrhizae: Rhizopogon, Cenococcuym, Cortinarius, Thelefora, Pisolithus and Suillus .
• Fungi present in orchideomycorrhizae : Xerotus, Ceratobasidium, Armillariella, Marasmius, Fomes, Corticium, Sebacina, Gymnopilus and Tulasnella .
• This is the type of fungus present in erichomycorrhizae: Pezizella.
• Types of fungi present in arbuscular mycorrhizae: Acaulospora, Gigaspora, Entrophospora, Glomus, Sclerocystis and Scutellospora.
• The fungus present in ectendomicorrhizae: Endogone.

If you like the world of fungi and that of vegetables or plants, you can learn more about them in these other AgroCorrn articles about the Fungi Kingdom: what it is, characteristics, classification and examples and the Plantae Kingdom: what it is, characteristics, classification and examples .

In addition, here below we leave you a video about the symbiosis so that you understand even better the relationship of mycorrhizae.