Mycorrhiza

Mycorrhiza- types and description

1. MYCORRHIZA P. Dhamodharan 2019502205 Department of Agronomy

2. MYCORRHIZA The word mycorrhiza was coined by the German scientist Albert Bernhard Frank in 1885. The word mycorrhiza is derived from the Greek words – ‘ mukes ’ meaning fungus and ‘ rhiza ’ meaning roots. Mycorrhiza (fungus-root) can be defined as a symbiotic association between fungi and plant roots .

3. Mycorrhizal fungi Mycorrhizal fungi colonize the plant’s root system and develop a symbiotic association called “ mycorrhiza ” They form a network of fine filaments that associate with plant roots and draw nutrients and water from the soil that the root system would not be able to access otherwise . Mycorrhizae are formed with more than 90% of plant species

4. Why Mycorrhizal Fungi Are Important   mycorrhizal -obligate assisting the host plant with the uptake of phosphorus and nitrogen increase the surface area associated with the plant root

5. Classification of mycorrhiza Based on tropic level by A.B. Frank Ectotropic Mycorrhiza Endotropic Mycorrhiza Based on morphological and anatomical feature Ectomycorrhiza Endomycorrhiza Ectendomycorrhiza

6. Broadly classified into Ectomycorrhiza (EcM) Endomycorrhiza (AM / VAM) Ectendomycorrhiza Monotropoid mycorrhiza Arbutoid mycorrhiza Orchid mycorrhiza Ericoid mycorrhiza

7. Ectomycorrhiza or ectotrophic mycorrhiza (EcM) Ectomycorrhizas , or EM, are typically formed between the roots of around 10% of plant families, mostly woody plants including the eucalyptus, oak, pine, deodar and rose families , orchids, and fungi belonging to the Basidiomycota , Ascomycota and Zygomycota . Commonly associated with trans temperate forest trees.

8. Ectomycorrhizal fungi form a sheath or mantle around the root, and hyphae emanate through the soil increasing the surface area. The fungus grows within the root cell wall but never penetrates the cell interior. It grows between the cells of the cortex to form Hartig net . The Hartig net present outside the endodermis and meristematic zones is the site for nutrient exchange . Colonization of root tips induces marked changes in the host root morphology.

9. Fungus forming ectomycorrhizae Amanita muscaria Boletus variegatus Paxillus invalutus Rhizopogon vinicolor Entomoloma Scle r o d end r an Amanita muscaria Entomoloma

10. Advantages of ectomycorrhiza Extensive multibranching hyphae increases the water holding capacity of plants. Increase the tolerance to drought, high soil temperature, organic and inorganic soil toxins, extremes of soil acidity to sulphur and aluminium. Deter infection of feeder roots by some rot pathogens. Enhance the uptake of many nutrients. (P, Cu, Zn through Hartig net) Disease control through barrier effect, competitive exclusion. Play a key role in afforestation.

11. Endomycorrhiza or endotrophic mycorrhiza Arbuscular mycorrhizae (often called AM) are the most common and widespread of all mycorrhizae and are found in as many as 85%-90% of the world's plant species. Commonly associated with agricultural, horticulture crops in addition to tropical trees.

12. The external hyphal mantle or sheath is absent or scanty . The fungal hyphae enters inside the root cortex and penetrates the cortical cells. This is not a destructive parasitic association but endomycorrhiza are present at certain times as a part of normal root development. AM fungi penetrate the cell walls of root cells. They grow between the cell wall and cell membrane forming arbuscules . VAM fungi produce vesicles for lipid storage.

13. Fungi forming endomycorrhizae Endogone Glomus Sclerocystis Acaulospora Gigaspora Enterophophora Scutellispora Glomus Gigaspora

14. Endomycorrhizae Ectomycorrhizae Generally fungi produce its typical structures, vescicles and arbuscules inside the root system. Fungi produce majority of its structure outside the root system. Commonly associated with agricultural, horticultural and tropical trees. Commonly associated with trans temperate forest tree roots. Have a loose network of hyphae in the soil and an extensive growth within the cortex cells of the plants. Form a complete mantle or sheath over the surface of the rot and hyphae grows out into the soil. Cannot be cultured on artificial media. Can be cultured on artificial media. Doesn’t cause morphological changes in roots. Cause morphological changes in roots.

15. Ectendomycorrhiza They share the features of both ecto- and endomycorrhiza. They have less developed hyphal mantle. The hyphae within the host penetrate its cells and grow within. These are found in both angiosperms and gymnosperms. Fungus associated are Ascomycetes. Hosts are Eucalyptus, Salix, Alnus etc.

16. Monotropoid mycorrhiza The family Monotropaceae, which includes achlorophyllous plants , develop the association. These plants entirely depend u pon the fungus for carbon and energy. S h e a t h , inte r - and in t racell u lar hyph ae and pe g -li k e hau s t o ria are present. Monotropa sp.

17. Arbutoid mycorrhiza These are found in the family Ericaceae. The fungi penetrate into the cortical cells forming extensive coils of hyphae. The mycosymbionts are Basidiomycetes. Sheath, inter- and coiled intercellular hyphae are present.

18. Orchid mycorrhiza At some point of time all Orchids are infected by orchidaceous mycorrhiza – Basidiomycota. Orchids germinate only after infection by mycorrhiza . Ex: Rhizoctonia sp. Within cells, hyphae form coils called pelotons which greatly increase the interfacial surface area between orchid and fungus.

19. Cymbidum orchid Orchid pelotons stained red in a light micrograph of sectioned tissue. Scaning electronmicrograph of orchid pelotons

20. Ericoid mycorrhiza This type occurs in the family Ericaceae. These plants have fine roots and the fungal members of ascomycetes like Pezizella, Clavaria forms the association in the outer region of cortical layer of roots. The ericoid fungal hyphae form a loose network over the hair root surface the hyphae can also penetrate the epidermal cells, often at several points in each cell and coiled hyphae fill the cell. Up to 80% of root volume can be fungal tissue and it is through these coils that nutrient exchange is thought to occur

21. Mycorrhiza Host range Types of relationship Ectomycorrhiza Gymnosperms and Angiosperms Sheath, intercellular hyphae Endomycorrhiza (VAM) All groups of plant kingdom Coiled intracellular hyphae, vesicle and arbuscules present Ectendomycorrhiza Gymnosperms and Angiosperms Sheath optional, inter and intracellular hyphae Monotropoid mycorrhiza Very restricted, Monotropaceae Sheath, inter and coiled intracellular hyphae Arbutoid mycorrhiza Very restricted, Ericales Sheath, inter and coiled intracellular hyphae Orchid mycorrhiza, Restricted, Orchidaceae Only coiled intracellular hyphae Ericoid mycorrhiza Very restricted, Ericales No sheath, no intercellular hyphae, long, coiled

22. C r op Mycorrhiza species Barley, maize, wheat Glomus spp. Bean Asaulospora morrowiae, Glomus, Gigaspora Pean u t Glomus fasciculatum, Sclerocystis dussi Pea Glomus intraradices C o t t on Glomus sp., Sclerocystis sinuosa Tomato, potato Gigaspora margarita, Glomus spp., Acaulospora sp. Black pepper Entrophosphora colombiana, Scutellospora sp. Carda m om Glomus fasciculautm Cit r us Glomus faciculatum, G. mosseae Mar i g o ld Glomus mosseae

23. Mechanism of symbiosis 1-Spore germination 2-Root colonisation 3-Exploration 4-Network development

24. Benefits of mycorrhiza Produce more vigorous and healthy plants. Increase plant establishment and survival at seedling or transplanting. Enhance flowering and fruiting. Increase yields and crop quality. Improve drought tolerance, allowing watering reduction.

25. Benefits of mycorrhiza Optimize fertilizers use, especially Phosphorus. Increase tolerance to soil salinity. Reduce disease occurrence. Contribute to maintain soil quality and nutrient cycling. Contribute to control soil erosion.

26. No mycorrhizal treatment Mycorrhizal treatment No mycorrhizal treatment Mycorrhizal treatment

27. Mycorrhizal effects on soil structure Greater water infiltration and water holding capacity More permeability to air Better root development Higher microbial activity and nutrient cycling Better resistance to surface sealing (crusts) Better resistance to erosion (water/wind) Better resistance to compaction

28. Application of VAM fungi Nursery application 100 g bulk inoculum is sufficient for one m 2 . The inoculum should be applied a 2-3 cm below the soil at the time of sowing. The seeds/cuttings should be sown/planted above the VAM inoculum to cause infection.

29. Application of VAM fungi For polythene bag raised crops 5 to 10 g bulk inoculum is sufficient for each packet. Mix 10 kg of inoculum with 1000 kg of sand potting mixture and pack the potting mixture in polythene bag before sowing . For out-planting 20 g of VAM inoculum is required per seedling. Apply inoculum at the time of planting. For existing trees 200 g VAM inoculum is required for inoculating one tree. Apply inoculum near the root surface at the time of fertilizer application.

30. Few mycorrhizal products available commercially

31. Advantages of Premier Tech Mycorrhizae Available in large quantities Superior quality inoculants (Pathogen-free – Homogeneous - Consistent quality) Great flexibility in formulation and applications Can be formulated at different concentrations Can be formulated with different carriers Can be formulated according to customer’s needs

32. THANK YOU