MYCORRHIZA - the symbiotic association of fungus and plants ,types and function

A fungus and a green plant have a symbiotic relationship known as a mycorrhiza. The fungus provides the plant with mineral nutrients, such as phosphorus, and water, while the plant produces organic molecules through photosynthesis and gives them to the fungus in the form of sugars or lipids.

1. MYCORRHIZA KIRTI KATHAIT

2. INTRODUCTION TYPES OF MYCORRHIZA FUNCTIONS OF MYCORRHIZA CONTENTS

3. “Mycorrhiza ’’was coined by Frank These are symbiotic association between certain types of soil fungi and the roots of most vascular plants Approximately 90% of vascular plants are associated with mycorrhizae Mycorrhizal like associations are also found in certain bryophytes INTRODUCTION

4. No mycorrhizal association - Brassicaceae and C henopodiaceae Non-mycorrhizal plants tend to grow in open habitats, where competition for soil nutrients may not be a major problem Root cap and root hairs are absent

5. TYPES ECTOMYCORRHIZA ENDOMYCORRHIZA

6. Hypha don’t penetrate individual cells within the roots Hypha grow externally, form fungal mantle and hartig net F orm visible reproductive structures Formed by mainly Basidiomycota and Ascomycota members R oot tips with fungal  mycelium  from the genus  Amanita Cross-section of part of a mycorrhizal root, showing the fungal sheath Hartig net. ECTOMYCORRHIZA

7. A  mere 3% of phanerogams form EcM.   Pinaceae  i s the oldest extant plant family in which symbiosis with EcM fungi occurs Examples : Amanita spp., Boletus spp.   and Tricholoma spp .  Boletus spp.

8. Hyphae penetrate the cell wall and invaginate  the cell membrane Increased contact surface area G reater transfer of nutrients between the two Glomeromycota ENDOMYCORRHIZA

9. TYPES OF ENDOMYCORHIZZA

10. M ost widespread F orm arbuscules and vesicles H igh affinity for phosphorus uptake Fungi are members of the phylum -Glomeromycota M embers of zygomycota - obligate symbionts Arbuscule vesicle ARBUSCULAR MYCORRHIZA

11. ERICOID MYCORRHIZA Plant species belongs to ericaceae family Fungi are members of the Glomeromycota F ound in acidic environments These form hyphal coils . A long with N and P helps in acquisition of minerals including iron, manganese, and aluminium Coiled hyphae inside epidermal cells.

12. T he orchid relies on the fungi to provide the nutrients, particularly carbohydrates In many cases orchid seeds will not germinate in absence of appropriate fungus F orm an association with the seedling once the seed coat has ruptured The hyphal coils called pelotons are formed within the cells example - basidiomycete genus Rhizoctonia ORCHID MYCORRHIZA SEM of orchid pelotons

13. Monotropaceae - achlorophyllous plants Dense sheath and Hartig net in outer corti­cal zone. Formation of fungal pegs Mostly found in coniferous forest Boletus is a mycorrhizal fungus asso­ciated with roots of both pine and Monotropa. MONOTROPOID MYCORRHIZA Monotropa uniflora Fungal pegs in Pterospora

14. Basidiomycetes members . Formed by the members of ericaceae family. Look similar to ectomycorrhizal fungi. T he hyphae penetrate the cortical cells of plant roots and form coils . Genera - Arctostaphylos and Arbutus ARBUTOID MYCORRHIZA Arctostaphylos virgata

15. FUNCTIONS N utrient efficiency Water absorption increases, plant resistance to drought Resistant to diseases For example , tomato - Phytophthora parasitica Excrete molecules like GLOMALIN ( glycoprotein). It improve soil aggregate stability and decrease soil erosion.

16. THANK YOU