With reference to agriculture.

1. MYCORRHIZA TYPES, DISTRIBUTION, AND SIGNIFICANCE
WITHREFERENCE TO AGRICULTURE.
PRESENTEDBY
SHABNOORSHAIKH
MSC1

2. OVERVIEWOF MYCORRHIZA
Mycorrhiza was first used by German researcher A.B. Frank in 1885.
It’s greek word viz mycos- fungus and
rhiza-root.
Symbiotic mutualisticrelationshipwithbidirectional nutrient
exchange.
About 90%of all land plants are associated with it except
Cruciferae, Chenopodiaceae and Resedaceae.

3. THREE WAY INTERACTION.
Mycorrhizal associationinvolves 3 way interactionbetween Host,
Fungi and Soil.
HOST PLANT
FUNGI
SOIL
FACTORS

4. TYPES OF ASSOCIATION
Mycorrhiza are commonly dividedinto endomycorrhiza and
ectomycorrhiza.
These two type are differentiated by-
Ectomycorrhiza do not penetrate individual cells withinthe root.
Endomycorrhiza penetrate the cell wall and invaginate the cell
membrane.

5. ENDOMYCORRHIZA
Endomycorrhiza’sare variable belonging to basidiomycetesand associated
with root development which have been furtherclassifiedas :-
Vesiculararbuscular mycorrhizae (VAM).
Ericoid mycorrhizae.
Arbutoid mycorrhizae.
Monotropoid mycorrhizae.
Orchid mycorrhizae.

6. VESICULAR ARBUSCULARMYCORRHIZA
VAMare produced by aseptate mycelial fungi whichpenetrateroot forming
vesicles and arbuscles.
Vesicles are thin or thick walled structure which stores polyphosphateand
other minerals.
Arbuscles are dichotomously branched haustoria which lives for 4 days and
then get lysed releasing storedfoodas oil droplets in the cortex.

7. ERICOIDMYCORRHIZA
Slowgrowing, septate and mostly sterile .
Rootlets are coveredby very loose, sparse, dark hyphae that penetrates the cortex
forming intercellular coils.
Thesecoils degenerate after 3-4 weeks likeVAM.
They usually improve the uptake of P and N nutritionof plants.

8. MONOTROPOIDMYCORRHIZA
Seen in Monotropaceae which are achlorophyllous.
Uses their mycorrhizae not only to obtain minerals and nutrients, but also to
tap the carbon supplies via the nearby plants or soil by breakdown of
cellulose and lignin.
Boletusa mycorrhizal fungus associatedwithroots of both pine and
Monotropa.
Fungal sheath present.

9. ORCHIDMYCORRHIZA
All orchids are myco-heterotrophic at some stage and formorchid
mycorrhizas with a range of basidiomycete fungi.
Their hyphae penetrate into the root cells and formpelotons (coils) for
nutrient exchange
The fungus provides C-nutrition to the seeds.

10. ECTENDOMYCORRHIZA (ARBUTOID)
They have mycorrhiza intermediate in formbetween ecto and endomycorrhiza
types found in ericaceae.
The root systemis differentiated in short and long roots.
Short roots are swollen and covered by mantle.
The formeractually penetrate the cortical cells and fill themwithcoils.

11. ECTOMYCORRHIZA
Theseare association, where fungi forma mantlearound roots withno hyphal penetration
in the cells.
Fungal hypha is generally separate.
Hartig’s net is present between
the cells whichis 40µmthick.
Most conspicuous and easily
recognized.

12. DISTRIBUTIONOR OCCURRENCE
OF ENDOMYCORRHIZA
Ubiquitous in Artic, Temperateand Tropical regionsfound in almost all
angiospermsincludinggymnosperms and liverworts.
Distribution pattern weresurveyed in montane scrubgrassland, alpine
steppe ad alpine meadow.
Their altitudes are rangingfrom3500 to 5200mon Tibetan plateau.
Their general occurrence is in Gramineae, Palmae, Rosaceae, Leguminosae
and Papilionaceae.
They are reported fromcarboniferousand Devonian periods.

13. DISTRIBUTION OR OCCURRENCE
OF ECTOMYCORRHIZA
Found in 3% of seeded plantsviz common in northern temperate forest
especially in Fagaceae and Pinaceae where as in tropics Myrtacceae and
Dipterocarpacae.
Majoritycomes fromthe general Amanita, Boletus and Tricholoma.
 Its distribution is limited to the arid areas of south-central Asia and the
northern hilly margin of the Tibetan Plateau.

14. SIGNIFICANCE WITHREFERENCE TO
AGRICULTURE
Increases nutrient uptake of plant fromsoil.
Increase diversity of plants.
Produce uniformseedling.
Significant role in nutrient recycling.
More tolerant to adverse soil chemical constraints which limit crop
production.
Inoculation of VAM as biofertiliser provides a distinct possibility for the
uptake of P in phosphorus-deficient soil.

15. Increases plant resistance to diseases and drought.
Improve soil structure.
Protection of plants during stress condition.
Uptake of sulphur and inorganic salts fromsoil.
Obligatory for the germination of orchidseeds.

16. CONCLUSION
Mycorrhizal association is very essential for the plants because it has
several benefits like absorption of nutrients, increase drought
resistance, enhance plant efficiency in absorbing water and nutrients
fromsoil.
AM fungi useful in agriculture because it serves as biofertilizers as it
helps in the absorption of phosphorus and other nutrient uptake.

17. REFERENCE
Introduction to mycology by R.S Mehrotra and R.K Aneja.
Principles of microbiology.