Mycorrhizal fungi are the fungi that form associations with the roots of plants that provide benefits for both the plant and the fungi. The fungi are responsible for linking soil with the plant by acting as an agent for nutrient exchange.
Types of mycorrhizal associations
There are four different types of mycorrhizal associations that are formed due to four different types of mycorrhiza.
- Arbuscular mycorrhiza
- Orchid mycorrhiza
- Ericoid mycorrhiza
Arbuscular mycorrhizal association is the most common type of association found in most of the agricultural plants, orchard plants and vegetables. Ectomycorrhizal association is more abundant in perennial plants and is less common in the disturbed ecosystems. Ornamental plants tend to form association with each of the four groups whereas orchid mycorrhizal association can only be found in orchid.
Benefits of mycorrhizal associations:
Mycorrhiza comes with a number of benefits. It can help plants in the uptake of trace elements along with phosphorus. It is done by the fungi by extending soil volume which is explored by the plant. Mycorrhizal fungi come with very thin hyphae. Each of the hyphae is between width of 1 to 10 thousandths of a millimeter. The hyphae explore around in the soil for gathering nutrients and then transport the same back to the host plant. Thus, it also helps in binding soil particles into aggregates.
Phosphorus, unlike nitrogen, does not move in the soil. So, the mycorrhizal fungi use this characteristic for helping the plant in the uptake of phosphorus from the soil. In case phosphorus is scarce in soil, plants with developed mycorrhizas on their roots gain greater access to phosphorus in soil and thus take up more phosphorus in comparison to others. Similarly, trace elements like zinc and copper also behave in the same way like phosphorus and thus the roots of plants need to explore the soil in order to intercept each of them. Mycorrhiza can also help in increasing the aggregation of soil. The hyphae of the mycorrhizas tend to form networks in between the neighboring soil particles, between roots of the same host plant, between the soil particles and roots and also between the roots of different plants. Not only that, but the hyphae also tend to form network inside the roots of the plant they colonize in. These networks formed by the hyphae are also known as mycelium. Mycorrhiza can also help in dealing with drought conditions.
Some other benefits of mycorrhiza:
- It helps in dealing with nutrient deficiency in plants.
- It helps in reducing the use of fertilizer for plants.
- It delays plant wilting. The fungi help in acquiring water from the areas where the roots of plants may not access it.
- It helps the plants in building up resistance to salt toxicity.
- It improves plant growth with improved acquisition of the required nutrients for the plants.