4.1 The ectomycorrhizas produced by Telephora terrestris on Pinus patula.
4.1.1 Morphological characteristics
The mycorrhizas are mostly bipodial (Fig. 1), rarely monopodial when young and becoming compactly clustered when old. Monpodial forms are slightly shorter and thinner (up to 6.7 x 0.6mm) when compared to the bipodial mycorrhizas (up to 9.0 x 1.0mm). The mycorrhizas are pale yellowish-brown (70S) in colour when young and dark-brown (7FS) when old. They are smooth with loose, straight hyphae emerging over the whole surface. Rhizomorphs are abundant, thread-like and growing on the surface of the mycorrhizal system; a few are attached directly to the mantle layer of the mycorrhizas. Rhizomorphs are similar in colour to the mycorrhiza system. Individual hyphae of the rhizomorphs are compactly arranged and are pale-brown (706) to dark-brown (7DS) in colour. Some loose hyphae radiate from the surface of the rhizomorphs.
4.1.2. Anatomical characteristics
4.1.2.1. Rhizomorphs: Therhizomorphs(Fig.4) are IS0-650 ~wide, and composed of closely packed, parallel hyphae covered with radiating hyphae. 1Wo types of hyphae are present: The hyphae of the central part are slightly wider (6-10 ~)
compared to those in the outer part (3-6 ~). The cell walls of the central hyphae are thinner (less than 0.5 ~) than those of the outer, surrounding, thick-walled hyphae (1-2 ~). Anastomoses between hyphae are frequent. Both the thin-walled central hyphae and thick-walled outer hyphae are septate with clamp connections. Septa and clamp connections are closer in the central, thin-walled hyphae than in the outer thick-walled hyphae. The hyphae radiating from the surface of the rhizomorphs arepale-brown (706) to dark-brown (708) and are similar in shape to the emanating hyphae of the mantle layer.
4.1.2.2. Mycorrhiza (cross section) (Fig. 2) : The mantle edge is 10-30 ~ deep and consists of a smiple prosenchymatous tissue. Numerous, hyaline to pale-brownish, emanating hyphae radiate from the surface. The emanating hyphae are up to ISO JUll long, mostly straight, with the distal ends sometimes slightly or distinctly bent. The emanating hyphae are typically branched near the mantle layer and are septate with
180 Techniques in Mycorrhizal Studies
Fig. 1
Fig. 2
Fig. 3
Fig. l. Thelephora terrestris. Habit (morphology of mycorrhizas) x 10.
Fig. 2. Thelephora terrestris. Transverse section of root x 445. C. Cortical cells;
H. Hartig net cells; M. mantle; T. tannin cells.
Fig. 3. Thelephora terrestris. Plan or surface view details of mantle layers. A.
Emanating hyphae, x 370; B. outer layer, x 1150; C. middle layer, x980; D.
innerlayer, x 1520.
K. Natarajan and V. Mohan 181
Fig. 4. Thelephora terrestris. Rhizomorphs x 640.
A
B
c
o
Fig. 5. Thelephora terrestris. Diagrammatic plan or surface view details of mantle layers. A. emanating hyphae, x 480; B. outer layer, x 1320 ; C. middle layer, x 1280; D. inner layer ,x 1980.
182 Techniques in Mycorrhizal Studies
clamp connections mostly in the basal part. The surface of the hyphae is smooth.
The hyphae are 3-5 J.UR in diameter basally and 1-2 J.UR in diameter distal1y. There are no cystidia, setae or seclerotia.
4.1.2.3. Tannin cells: are mostly in a single row, elliptical to elongate, pale-yellow (3A3) to yellowish-brown (508) and are 25-55 J.UR x 10ã30 J.UR in size. The Hartig net
is composed of a single row of oval to rectangular hyphal cells, 3-6 J.UR thick.
4.1.2.4. Cortical cells: are round or slightly elliptical and 20-70 J.UR in size. The Hartig net is composed of a single row of oval to rectangular hyphal cells, 3 -6 J.UR and penetrate to a depth of up to three cortical cell layers.
4.1.2.5. Mycorrhiza mantle (plan or surfaceview) (Figs. 3 and 5) : The mycorrhizas in plan view have three mantle layers. The outer layer is composed of a net prosenchymatous tissue with loosely interwoven hyphae, 3-8 J.UR in diameter and septate with clamp connections. The middle layer consists of a net prosenchymatous tissue with densely packed hyphae, 4-10 J.UR in diameter and septate with infrequent clamp connections. The inner layer is composed of an irregular synenchymatous tissue with compactly arramged hyphae, 2-6 J.UR in diameter.
4.2 The ectomycorrhizas produced by Amanita muscaria on Pinus patula
4.2.1 Morphlogical characteristic
The mycorrhizas are mostly of the bipodial and dense clustered forms (rarely monopodial). They are short and stubby when young and tortuous with frequent, irregularly spaced branches, often forming quite dense clusters, when old (Fig.6), The mycorrhizas are white to silver-white when young and greyish-white (1B I) to light yellowish-white (4A2) when old.
The surface of the mycorrhiza has silver-white tints. When the mycorrhizas are bruised or kept in formalin/acetic acid! alcohol (FAA), the white tints disappear and they become greyish-white to yellowish-white. The surface ofthe mycorrhizas are smooth when young and slightly roughened and distinctly granular in appearance when old. The rhizomorphs are milky- white to greyish-white(IB 1) in colour. They grow on the surface of the mycorrhizal system, a few being directly connected to the mantle layer of the mycorrhizas.
4.2.2 Anatomical characteristic:
4.2.2.1. Rhizomorphs: The rhizomorphs are 50-125 J.UR wide and composed of closely packed hyphae which are parallel, thin-walled, septate and without clamp connections. The hyphae are white to greyish-brown (7E2) in lactophenol.
Anastomoses between hyphae are infrequent.
K. Natarajan and V. Mohan 183 4.2.2.2 Mycorrhiza(cross section) (Fig.7): The mantle edge is 15-30 IllIUieepand consists of a simple, prosenchymatous tissue. Hyaline to greyish-white (lBI) emanating hyphae emerge from the surface of the mantle. The emanating hyphae are up to 90 lUll in length, slighty tortuous, slender, thin-walled, septate and without clamp connections. The distal ends of the emanating hyphae are slightly broader (3-5 lUll wide) than those of the basal region (2-3 lUll wide). The blunt, broder hyphal tips look like cystidia; there are no setae or sclerotia.
4.2.2.3 Tannin cells: are mostly in a single row, elliptical to slightly elongate, 25- 50x 10-30 lUll in size and pale brown (5D6) to yellowish-brown (5D8) in colour. The Hartig net is composed of a single row of oval to globose hyphal cells 3-5 lUll in thickness and penetrates up to three cortical cell layers deep.
4.2.2.4 Cortical cells: are elliptical and 30-50x20-30 lUll in size. The Harting net is composed of a single row of oval to globose hyphal cells, 3-5 .. m in thickness and penetrats up to three cortical cell layers deep.
4.2.2.5. Mycorrhizamantle (plan or surface view) (Figs. 8 and 9): Themycorrhizasin plan view have three different layers of mantle. The outer layer is composed of a felt made of prosenchymatous tissue. The individual hyphae of this layer are loosely interwoven, septate, 2-5 lUll in diameter and without clamp connections. The middle layer consists of densely packed, net prosenchymatous tissue with individual hyphae similar to those of the outer layer. The inner layer is composed of a net synenchymatous tissue, the hyphae of which are septate and 5-7 lUll in diameter.
The distinguishing features of the mycorrhizas produced by A. muscaria are as follows:
1. The mycorrhizas produced are short, stubby and dichotomously branched to complex clustered.
2. The mycorrhizas are milky-white to silver-white. Silver-white tints seen on the surface of the mycorrhizas disappear when bruised or when the mycorrhizas are kept in FAA.
3. The mycorrhizas are smooth to slightly granular. This granular apperance is due to the presence of distinctive cystidium-like emanating hyphae on the surface of the mantle layer. The emanating hyphae are septate and without clamp conncetions.
4.3 The ectomycorrhizas produced by Laccaria laccala onPinuspatula.
4.3.1 Morphological characteristic
The mycorrhizas are mostly dichotomously branched (bipodial) and rarely mono-, tri-and tetrapodial. They are slightly tortuous and fairly long with frequent, irregularly spaced, short branches (Fig. 10). The main axis is up to 5.5 mm in length and up to 0.6 mm in diameter. The mycorrhizas are white when young and whitish-orange to greyish-brown (6D3) when old.
Loose, hyaline hyphae are associated with the surface of the mycorrhizal
184 Techniques in Mycorrhizal Studies
Fig. 6
Fig. 7
''''''. ;;~ :I/?ã I~'
'0 ~ .... "..1
'.-' .
. ...
Fig. 8
Fig. 6. Amanita muscaria. Habit (morphology of mycorrhizas) x 10.
Fig. 7. Amanita muscaria. Transverse section of root x 480. C. Cortical cells; H.
Hartig net cells; M. mantle.
Fig. 8. Amanita muscaria. Plan or surface view details of mantle layers. A. outer layer, x 660; B. middle layer, x 1760; C. inner layer, x930.
K. Natarajan and V. Mohan 185
A
B
c
o
Fig. 9. Amanita muscaria. Diagramatic plan or surface details of mantle layers. A.
Emanating hyphae, x 515; B outer layer, x 440; C middle layer, x 1450; D inner layer, x 880.
system and are just visible under the dissecting microscope. The surface of the mycorrhiza is pubescent. There are no rhizomorphs or hyphal strands.
4.3.2 Anatomical characteristics (Fig. I I)
The mantle edge is 10-50 !lm deep and consists of a simple, felt of prosenchymatous tissue overlying net prosenchymatous tissue. White or pale orange (5 A3) to pale brown (6D4) emanating hyphae emerge from the mantle surface. The emanating hyphae are up to 138 !lm long, mostly tortuous, thin-walled, 2-5 /lID wide and septate with abundant clamp connections. Branches ofthe emanating hyphae are rarely present. There are no cystidia, setae or sclerotia.
186 Techniques in Mycorrhizal Studies
4.3.2.1 Tannin cells: are mostly in a single row, subglobose to elongate, 20-45x1 0ã30
~ in size and pale orange-yellow (4A7) to brownish-orange (6C6). The Hartig net is composed of one or two rows of oval to globose hyphal cells, 3-8 ~ thick.
4.3.2.2 Mycorrhizamantle (plan or surface view) (Figs. 12 and 13) : Themycorrhizas in plan view have three different layers of mantle. The outer layer is composed of a felt made of prosenchymatous tissue. The individual hyphae of this layer are 3-8 ~
wide and septate with frequent clamp connections. The middle layer consists of an net prosenchymatous tissue. The hyphae are similar to those of the outer layer with few clamp connections. The inner layer is composed of a net synenchymatous tissue with hyphae 3-5 ~ in diameter. The distinguishing features of the mycorrhizas produced by L. laccata are as follows :
1. The mycorrhizas are typically short and dichotomously branched structures.
They are white to yellowish-white when young, turning greyish-brown (603) when old. The surface is pubescent with hyaline, loose hyphae.
Morphologically it is not easy to differentiate this mycorrhiza from young mycorrhizas produced by Telephora terrestris.
2. Rhizomorphs or hyphal strands are not present, un-like the mycorrhiza formed by T. terrestris.
4.4. The ectomycorrhizas produced by Suillus brevipesvar. brevi pes on Pinus patula.
4.4.1 Morphological characteristics
The mycorrhizas are mostly monopodial and bipodial and a few are tri- and tetrapodial (Fig. 14). They are generally striaight or slightly tortuous.
The mycorrhizas are slightly broader at the base than at the tip. The main axis is 1.2-S. 4mm in length and 0.2-0. 4mm in diameter. The mycorrhizas are pale yellow (4A3) to yellowish-brown (5DS) when young and pale brownish-yellow (5CS) to reddish-brown (SE8) when old. The surface is smooth when young and striations are seen when old. Loose hyphae are attached to the surface of the mycorrhizas, sometimes surrounding them as a loose web. These hyphae are thin, undulating and pale yellow (1A2) to yellowish-brown (5D8). There are no rhizomorphs or hyphal strands.
4.4.2 Anatomical characteristics
4.4.2.1 Hyphae surrounding the mycorrhizas : These hyphae are thin walled, 5ã7
~ wide, septate, without clamp connnections and are pale yellow (lA2) to yellowish- brown (508). Anastomosing is infrequent.
4.4.2.2 Mycorrhiza (cross section) (Fig. 15) : The mantle edge is 10-15 ~ deep and consists of simple, prosenchymatous tissue. White to pale yellowish-brown, emanating hyphae radiate from the surface of the mantle layer. The emanating
K. Natarajan and V Mohan 187
Fig. 10
Fig. II
Fig. 12
Fig. 10. Laccaria Iaccata. Habit (morphology ofmycorrhizas) x 10.
Fig. 11. Laccaria Iaccala. Transverse section of root x 460. C. Cortical cells; H.
Hartig net cells: M. mantle : T. tannin cells.
Fig. 12. Laccaria Iaccala. Plan or surface view details of mantle layers. A.
emanating hyphae, x 350; B. outer layer, C. middle layer, x 1040; D. inner layer, x 1600 ..
188 Techniques in Mycorrhizal Studies
c
o
Fig. 13. Laccaria laccala. Diagrammatic plan or surface view details of mantle layers. A emanating hyphae, x 260 ; B outer layer, x 560 ; C middle layer, x 645; D inner layer, x 940.
hyphae are 30-140 JUIllong, mostly tortuous, 3-4 JUIl wide, septate and without clamp conncetions. The surfaces of the emanating hyphae and the mantle hyphae are slightly encrusted. There are no cystidia, setae or sclerotia.
4.4.2.3 Tannin cells : are mostly in a single row, elliptical, 20-55xlO-40 JUIlin size. The Harting net is composed of a single row or rectangular hyphal cells, 2-4 JUIl thick.
4.4.2.4 Cortical cells: are slightly oval to elliptical and measure 20-50xlO-20 JUIl. The Hartig net is composed of a single row of rectangular hyphal cells 2-4 JUIl thick and penetrates up to three cortical cell layers deep.
4.4.2.5 Mycorrhizamantle (plan or surface view) (Figs. 16 and 17) : The mycorrhizas in plan view have three different layers of mantle. The outer layer is composed of a simple, prosenchymatous tissue, the hyphae of which are hyaline, septate, 2-4 JUIl in diameter and without clamp conncetions. The middle layer is composed of a net prosenchymatous tissue with hyphae similar to those of the outer layer. The inner layer consists of an irregular, synechymatous tissue with hyphae 2-3 JUIl in diameter.
The distingushing features of the mycorrhizas produced by S. hrevipes are as follows:
K. Natarajan and V. Mohan 189 (i) Rhizomorphs or hyphal strands are not seen on the mycorrhizal system.
Instead, loose hyphae sometimes surround the mycorrhizal system as a loose web.
(ii) The emanating hyphae that radiate from the mantle edge are septate and without clamp conncetions.
(iii) The surface of the emanating hyphae and the mantle hyphae are slightly encrusted with granulations.
4.5 The ectomycorrhizas produced by Rhizopogon luteolus on Pinus patula
4.5.1 Morphological characteristics
The mycorrhizas are usually highly dichotmously branched, complex coralloid forms, rarely bipodial or monopodial. They are stubby (short, thick and finger-like) and compactly branched (Fig. 18). The main axis is up to 2. Omm in length and up to 0.6mm in diameter. The mycorrhizas are whitish-to brownish-yellow (5CS) when young and light brown (50S) when old. The surface is pubescent with fine sepia-coloured (dark brown) hyphae. Rhizomorphs are abundant, long, rope-like, compactly arranged, thick (up to 0.3 mm in diameter), and light yellow (4A5) to brownish- yellow (5C8). They are directly connected to the mantle layer of the mycorrhiza system.
4.5.2 Anatomical characteristics
4.5.2.1 Rhizomorphs (Fig. 21) : Therhizomorphs are 30-155 JU1l wide and composed of closely packed, thin-walled, septate and nonclamped hyphae. Individual hyphae are pale yellow (3A3) to yellowish-brown (5D8) in colour. Anastomoses between hyphae are occasionally present. Prominent, warty encrustations are present on the outer surface of the rhizomorph hyphae.
4.5.2.2 Mycorrhiza (cross section) (Fig. 19) : The mantle edge is 20-45 ~ deep and cosists of plectenchymatous tissue. Pale whitish to yellowish-white emanating hyphae radiate from the surface of the mantle. The emanating hyphae are 20-110 JU1l long, mildly tortuous, thin-walled, septate and without clamp connections. There are no cystidia, setae or sclerotia.
4.5.2.3 Tannin cells : are mostly in a single row, elongate, 25-45x5-15 JU1l in size and yellowish-brown (5D8) to dark-brown (6P5) in colour. The Hartig net is composed of a single row of rectangular hypha! cells 3 -4 JU1l thick.
4.5.2.4 Cortical cells: are broadly elliptical and measure 25-45 x 20-40 JU1l in size.
The Harting net mainly consists of a single row of rectangular hyphal cells 3 -4 ~
thick and penetrates up to three cortical cell layers deep.
4.5.2.5 Mycrrohiza mantle (plan or surface view) (Figs. 20 and 22) : The mycorrhizas in plan view have three different layers of mantle. The outer layer is composed of a
190 Techniques in Mycorrhizal Studies
Fig. 14
Fig. 15
Fig. 16
Fig. 14. Sui/lus brevipes. Habit (morphology of mycorrhizas) x 10.
Fig. IS. Sui/lus brevi pes. Transverse section of root x 560. C. cortical cells; H.
Hartig net cells; M. mantle; T. tannin cells.
Fig. 16. Sui/lus brevi pes. Plan or surface view details of mantle layers. A. outer layer, x 500; B. middle layer, x 480; C. inner layer, x 400.
K. Natarajan and V. Mohan 191
Fig. 17. Suillus brevipes. Diagrammatic plan or surface details of mantle layers. A.
emanatig hyphae, x 1300; B. outer layer, x 1820; C. middle layer, x 1740; D.
innerlayer, x 1620.
plectenchymatous tissue in which the hyphae are loosely woven. The individual hyphae of this layer are superimposed on each other and may be branched or unbranched. They are 3-6 ~ in diameter, septate and without clamp connections.
The middle layer is composed of a plectenchymatous tissue which is more compact than that of the outer layer. The cell walls of individual hyphae are up to 1 ~ in thickness, and the hyphae are 3-6 ~ in diameter, septate and without clamp connections. The inner layer consists of a net synenchymatous tissue with elongated, more densely packed hyphae, 3-5 ~ in diameter.
The distinguishing features ofthe mycorrhizas produced by R. luteolus are as follows :
1. The mycorrhizas are typically short, stubby and compactly branched coralloid forms. The surface is pubescent with fine sepia-coloured hyphae.
2. Rhizomorphs are abundant, directly connected to the mantle layer of the mycorrhizas and of the same colour as the mycorrhiza system. Prominent, warty encrustations are visible on the surface of the rhizomorphs when the hyphae are mounted in cotton blue.
3. The emanating hyphae radiating from the mantle surface are septate and without clamp connections.
192 Techniques in Mycorrhizal Studies
4.6 Ectomycorrhizas produced by Sclerodermacitrinum onPinuspatula 4.6.1 Morphological charateristics
The mycorrhizas are generally bipodial and complex clustered coralloid structures, rarely mono-or tripodial. They are elongated, compactly branched and mildly tortuous, occasionally straight (Fig. 23). The main axis is 1. 0-6.0 mm in diameter. The mycorrhizas are smooth when young and slightly granular to woolly or velvety when old. Rhizomorphs are abundant, long and tread-like, pure milky white to dull white in colour.
They grow on the surface of the mycorrhizas with a few attached directly to the mantle layer. Some loose hyphae radiate from the surface of the rhizomorphs.
4.6.2 Anatomical characteristics
4.6.2.1 Rhizomorphs (Fig. 26) : The rhizomorphs are 2S-90 J.IlIl wide and composed of closely packed hyphae which are parallel, undulating, thin-walled and septate with frequent clamp connections. Individual hyphae are yellowish-white (4A2) to yellowish-grey (4B2). Anastomoses between hyphae are frequent. Some hyphae radiate from the main branch of the rhizomorphs and have distal ends swollen like cystidia. These radiating hyphae are similar in shape to the emanating hyphae of the mantle layer.
4.6.2.2 Mycorrhiza (cross section) (Fig. 24): The mantle edge is IS-SO JUll deep and consists of a loosely woven, felt of prosenchymatous tissue. Numerous hyaline to greyish-white (lBI) emanating hyphae emerge from the surface of the mantle.
The emanating hyphae are SO-130 J.IlIllong, mostly straight (a few slightly tortuous) thin-walled and septate with clamp connections. The distal ends of the emanating hyphae are broader (4-7 JUll in diameter) than those of the basal region (2-4 J.IlIl in diameter) and these swollen tips resemble cystidia. Otherwise there are no cystidia, seta or sclerotia.
4.6.2.3 Tannin cells: are mostly in a single row (in a few cases in one or two rows), cylindric to slightly elongate, 2S-65xl 0-30 J.IlIl in the size and greyish-yellow (2A6) in colour. The Harting net is composed of a single row of oval to spherical hyphal cells, 2-4 J.IlIl thick.
4.6.2.4 Cortical cells: are broadly elliptical to slightly elongate, 30-70xlS-SO J.IlIl.
The Harting net is composed of a single row of oval to spherical hyphal cells 2-4 JUll thick and penetrates up to three cortical cell layers deep.
4.6.2.5 Mycorrhiza mantle (plan or surface view) (Figs. 2S and 27) : Themycorrhizas in plan view have three different layers of mantle. The outer layer is composed of a felt prosenchymatous tissue. The individual hyphae of this layer are loosely interwoven, elongated, thin-walled, 3-S JUll in diameter and septate with frequent clamp connections. The middle layer consists of felt made of prosenchymatous tissue. The individual hyphae of this layer are loosely interwoven, 3 -S ~m in diameter
K. Natarajan and V. Mohan 193
Fig. 18
Fig. 19
'.~~ '~~-. -
' ...
•. 'c-. d,ã .. .-,,_-'
Fig. 20
Fig. 18. Rhizopogon luteo/us. Habit (morphology of mycorrhizas) x 10.
Fig. 19. Rhizopogon luteo/us. Transverse section of root x 460. C. cortical cells;
H. Hartig net cells ; M. mantle.
Fig. 20. Rhizopogon /utelous. Plan or surface view details of mantle layers. A emanating hyphae, x 850 ; B outer layer, x 1200 ; C middle layer, x 1350; D.
innerlayer, x 1050.