by Pratik M.



Hartig Net


Two predominant types of mycorrhizae


  1. live only on the outside of the root.

  2. Relationships are characterized by an intercellular surface known as the Hartig Net(wooly covering)

  3. Ectomycorrhiza tend to form mutual symbiotic relationships with woody plants

  4. only 5-10% of terrestrial plant species

  5. birch, beech, willow, pine, oak

  6. ectomycorrhiza can be identified by the mantle


  1. lives inside of the root hyphae outside the root.

  2. relationships are characterized by a penetration of the cortical cells by the fungi and the formation of arbuscules and vesicles by the fungi.

  3. Endomycorrhiza have an exchange mechanism on the inside of the root, with the fungi’s hyphae extending outside of the root.

  4. some hyphae send small projection into cortical cell without destroying them.

  5. over 80% of terrestrial plant species

  6. bryophytes and pteridophytes

  7. Sub division zygomycotina

Hartig NetThe Hartig Net consists of highly branched hyphae connecting the epidermal cells and cortical root cells.

Mantle The formation of a dense hyphal sheath (10 μm) surrounding the root’s surface. This is known as the mantle

Vesicle The mycelium of mycorrhizae enters the host plant cell and forms a sac-like organ called vesicle.

  • store polyphosphates and other metals through which fungal mytozoa

  • supply phosphate to plant roots.

Arbuscules some hyphae in endomycorrhizae send small projection into cortical cell without destroying them.

  • Endomycorrhiza are further subdivided into specific types


Phosphate nutrition and growth production

Importace of Phosphate

The three major nutrients- nitrogen, phosphorus and potassium required by plants. Among these nutrients, phosphorus constitutes a critical component because on one hand it is limiting for crop yield and, on the other hand, it is a non-renewable resource.

Why Mycorrhizal Symbiosis

In soil, phosphorus (P) is present in different pool

  • one is organic phosphorus (Po)

  • inorganic phosphorus (Pi)

  • Only a small amount is directly accessible to plants as solubilized Pi. Plants take up P from soil as Pi.

  • Therefore, P is one of the major limiting nutrient elements for plant growth.

  • The diffusion rate of Pi in the soil is very low as a result a depletion zone arises around the roots.

  • To overcome the Pi limitation in the rhizosphere, the formation of symbiotic structures with mycorrhizal fungi is considered as the most widespread response to increase P uptake by plants

Why mycorrhizal plants accumulate more P than non-mycorrhizal plants

  1. the hyphal network is very efficient in nutrient uptake due to its large surface area. (very extensive in the soil and increase the absorbing area of roots.)

  2. phosphorus is a highly immobile element due to which Depletion zone occurs. Extra radical hyphae extend beyond this depletion zone, absorbing bio-available phosphate that is otherwise not accessible to the plant

The AM pathway can reduce the impact of Pi depletion in the rhizosphere and so improve plant P nutrition and growth. The extent to which an AM plant grows better than a non-mycorrhizal (NM)

Depletion zone

Phosphate is easily absorbed by soil particles and a phosphate free zone rapidly occurs around plant roots. This is Depletion zone.


Applicatin of Azolla as biofertilizer


Rice duck Azolla

Allpication as Biofertilizer

Azolla can be applied in paddy fields in two ways.

  1. Azolla biomass can be applied to the soil before sowing plants

  2. post-sowing.


  • The height of the water should be determined as 10 cm.

  • Collecting and processing Azolla biomass from nursery plot and it should be added directly to the land at the rate of 15 tons/hectare


  • In case of post-planting application, Azolla is applied directly as 500 kg per hectare 7 days after planting.

  • Soil water depth must be 5-7.5 cm.

  • Azolla mat will form in soil four weeks after planting.

  • In this way Azolla mats can be formed for the second time after four weeks by inoculating a second time on the same plot. Thus biomass production of Azolla up to 20-25 tonnes is possible from two inoculation plots.


  1. Azolla floats in ground water and forms a mat so sunlight cannot reach ground water properly. As a result the ground water elevation is about 1° lower than normal. This low humidity creates an unfavorable environment for weed growth in the soil.

  2. Azolla's dense mats block sunlight from reaching the soil, inhibiting weed seed germination, thereby reducing weed infestation. Azolla is called a bioherbicide for the above two reasons. 33.3% Azolla milotica

  3. Nutrients present in flood water cannot be directly absorbed by rice plants.

    • Azolla can store these nutrients inside its body.

    • Vegetative elements are added to the soil when the bodies of plants are incorporated into the soil after death.

    • This process is called mineralization.

  4. The pH of floodwaters present beneath mats of Azolla never reaches alkaline levels. Thus the former Azolla prevents the loss of ammonia from the soil by preventing the pH from reaching alkaline levels.

Rice Duck Azolla

Above all, nitrogen fixation by Azolla can occur at a significant level that is appreciable for increasing productivity in rice. It has been found that 3-5 kg ​​of nitrogen can be fixed by Azolla per hectare per day under favorable conditions. Rice-duck-Azolla integrated cultivation method (Integrated System of Cultivation) has been introduced in Japan. With this method it is possible to avoid pesticide application in rice. Duck and Azolla are reared together in paddy fields. Azollas are consumed by ducks during migration in ground water. As this food is rich in protein and antioxidants, it increases the growth and egg production capacity of ducks. The droppings that the ducks make while roaming the land are again used as a phosphate source for Azolla. Not only this, it also acts as a phosphate source for rice. Ducks feed on rice and Azolla pests while roaming, eliminating the need for pesticide application. In addition, dense growth of Azolla prevents weeds from growing in paddy fields. Thus it is possible to get multiple benefits by rearing rice, duck and Azolla together


Pratik M.


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