A part of Botany (Hons) syllabus in Mycopathology illustrates the basic differnces in ectomycorrhizae and endomycorrhizae as well as their significance

1. ECTOMYCORRHIZAE,
ENDOMYCORRHIZAE AND THEIR
SIGNIFICANCE
Botany (Hons) Sem II CC-3; Unit 8
(Ref : G. Hait, A textbook of Mycology, NCBA;)
Dr. Rita Som Paul
Associate Professor
Botany Department
Siliguri College
Siliguri

2. WHAT IS MYCORRHIZA?
 ‘Mykes’- mushroom (Gr.)
 ‘rhiza’ – root
 Symbiotic association between plant root and fungi
with biderectional exchange of of nutrients between
the partners
 Named so by A.B. Frank (1885)
 About 90% of all land plants are associated with
this phenomenon

3. TYPES OF MYCORRHIZAE
 (Peterson & Farquhar, 1994):
 1. Ectomycorrhizae
 2. Vescicular-Arbuscular mycorrhizae (VAM)
 3. Ectendomycorrhizae (arbutoid)
 4. Ericoid mycorrhizae
 5.Gentianoid mycorrhizae
 6. Orchidoid mycorrhizae
 7. Monotropoid mycorrhizae
 Bradly speaking, there are three types- ecto, ectendo and
endo.
 Endomycorrhiza includes arbuscular, ericoid, and orchid
mycorrhiza, while arbutoid mycorrhizas can be classified
as ectoendomycorrhizas. Monotropoid mycorrhizas form a
special category.


4. ECTOMYCORRHIZAE (ECM)
 ‘ sheathing mycorrhiza’
 Occur in 3% of all seed plants
 Fungus enters cortex forming “Hartig Net” but never
inside the endodermis or stele
 Intercellular hyphae( extracellular)
 In northern temperate regions, plants such as pine
(Pinus), spruce (Picea), fir (Abies), poplar (Populus),
willow (Salix), beech (Fagus), birch (Betula) and oak
(Quercus) typify the ECM association. In the
southernhemisphere Eucalyptus and Northofagus (Sout
hern Beech) are important genera as is the
Dipterocarpaceae
 Fungi- Basidiomycota (Amanita muscaria, most
Agarics). Ascomycota (Boletus spp, Tuber magnatum
etc); Zygomycete genus Endogone,

5. SOME MACROSCOPIC IMAGES OF ECTO
Tuber magnatum
(Ascomycota)
Amanita muscaria
(Basidiomycota)

6. SOME MACROSCOPIC IMAGES OF ECTO-
Ref : Moore et al, 2011;
mycorrhizas.info
Small parts of root systems.
A-D- Douglas fir (Pseudotsuga
metziesii); A-with truffle Hysterangium;
B-with basidiomecete Rhizopogon
vinicolor;C-with polypore Bissoporrya
terrestris; D-with Lactarius
sanguiflurus;E- A.muscaria with Picea
sitchensis; F- A.muscaria with Pinus
radiata; E- Pinus sp seedling with
Siullus bovinus in experimental
microcosm

7. SOME MICROSCOPIC IMAGES OF ECTO-
A. TS of ectomycorrhizal Tsuga
canadensis (hemlock) with
labyrinthine Hartig net hyphae
(arrows) penetrating between the
cortical cells of the root and
completely surrounding many
cells; note tannin-filled epidermal
cells in the inner mantle (asterisk);
scale bar = 100 µm)
B. root cross-section of
ectomycorrhizal Populus
tremuloides (quaking or trembling
aspen) showing labyrinthine Hartig
net hyphae (arrows) around
elongated epidermal cells.

8. SOME MICROSCOPIC IMAGES OF ECTO-
Hartig net in Pinus sp.

9. IMPORTANCE OF ECTOMYCORRHIZA
 Enhances nutrient and water absorption by increase in
surface are
 Nutrient mobilization through biological whithering
 Enhances uptake of N,P,K, Ca, NA,Fe,Zn, S and Mo and
translocation
 Enhances degradation of complex minerals and organic
substances
 Provide protection against pathogens by physical
barrier, by favouring growth of beneficial rhizosphere
microorganisma and use of surplus carbohydrate
 Provides host plant with hormones (auxin, cytokinin,
gibberellin ) and vit B

10. ECTOMYCORRHIZA VS ENDOMYCORRHIZA

11. ECTOMYCORRHIZA(ECM) VS ENDOMYCORRHIZA
(VAM/AM)
Ecto/ECM Endo- VAM/AM
Hyphae are only intercellular both – inter and intra cellular
thick fungal mat (mantle) around
the roots
Mantle absent
Formation of Hartig net No Hartig net
Vesicles and arbuscules are
absent
Vesicles (one celled) and /or
arbuscules (dichotomous) are
present
Separate type of mycorrhiza Includes AM/VAM, ericoid,
and orchidoid mycorrhiza,
Fungal partner is
Basidio/Ascomycota
Eg Amanita muscarina; Tuber
melanospora
Fungal partner belongs to
Zygomycota, occasionally
Basidiomycota
Eg. Glomus sp, Gyrospora sp
Rhizoctonia sp, Corticium sp
Cause extensive branching and
growth of roods
No such effect

12. MAICROSCOPIC IMAGES OF
ENDOMYCORRHIZAE
Arbuscular Glomus on Allium

13. IMPORTANCE OF ENDOMYCORRHIZA
 Mycorrhizal association is obligatory for germinating
orchid seeds. Egs Rhizoctonia repens and Orchis
militaris
 Inoculation of VAM as biofertilizer provides possibility of
uptake of P in P- deficient soils
 Trees with endomycorrhizae act as first invaders in
wastelands and pioneers in barren land.
 Root colonizatin provides protection from parasitic fungi
and nematodes
 Crops like onion, strawberry, corn etc depend on
mycorrhiza in absence of P
 Can be cultured on maize and sudan grass for mass
inoculum multiplication
 Help in uptake of mineral ionsand act as reservoir.

14. END NOTE:
 Mycorrhizae play a very important role in agriculture
and forestry.
 In spite of the differences in structure, both the
types help in uptake of nutrients and protect from
plant pathogens
 Ectomycorrhizae have mostly macroscopic fruit
bodies and more associated with forest ecosystem
 Till now, most of the endomycorrhizae studied are
only microscopically visible and associated with
cultural crops like tea and maize