The genus Dermatosorus (Ustilaginales)

The genus Dermatosorus (Ustilaginales)

[ 61 ] Trans. Br. mycol. Soc. 89 (1), 61--65 (1987) Printed in Great Britain THE GENUS DERMATOSORUS (USTILAGINALES) By KALMAN V ANKY Lehrstuhl Spezi...

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[ 61 ] Trans. Br. mycol. Soc. 89 (1), 61--65 (1987)

Printed in Great Britain

THE GENUS DERMATOSORUS (USTILAGINALES) By KALMAN V ANKY Lehrstuhl Spezielle Botanik der Universitiit Tubingen, Auf der Morgenstelle D-7400 Tiibingen 1, W. Germany

1,

After a short historical review, a revised description of the genus Dermatosorus is given. Zundelula is included in Dermatosorus. Two new combinations are proposed: Dermatosorus bulbostylidis (Thirum. & Pavgi) Vanky and D. thirumalacharii (Pavgi & Giri) Vanky. A key to the species is compiled and the four known Dermatosorus species are fully described. Dermatosorus is also compared with the genus Moesziomyces. The genus Dermatosorus was erected by Sawada (in Ling, 1949) to accommodate an interesting smut, forming peculiar spore balls in the ovaries of Eleocharis dulcis, collected in Taiwan. Thirumalachar & Narasimhan (1952) described a new genus, Zundelula, which' is closely related to Dermatosorus Sawada'. Langdon (1977) studied the types of these genera, Zundelula fimbristylidis and Dermatosorus eleocharidis, and concluded that' The origin of the sporogenous hyphae and the pattern of spore ball development in Z. fimbristylidis are the same as in D. eleocharidis'. Consequently, he transferred Zundelula fimbristylidis to the genus Dermatosorus, and considered Zundelula to be a synonym of Dermatosorus. A study of the types of the genera Dermatosorus and Zundelula showed, in concordance with Langdon (1977), that all major characters of these two genera are identical. The sori, formed in scattered, swollen ovaries, are filled with darkcoloured spore balls. The spore balls, produced from a central columella, ripen gradually from their distal part. They are composed of numerous fertile spores, embedded in a pseudoparenchymatous tissue of fungal origin, surrounded by a cortex of sterile cells. The fact that the cortex of the spore balls are formed of firmly- or loosely-united sterile cells is not a sufficient reason to keep these species in two different genera, and therefore they are treated here under the older generic name Dermatosorus. Two other species of Zundelula are already described: Z. thirumalacharii Pavgi & Giri (1966),

and Z. bulbostylidis Thirumalachar & Pavgi (1967), which show the same sorus and spore ball structure, as well as spore ball development pattern, as in Dermatosorus eleocharidis, the type of the genus Dermatosorus , and therefore the names are transferred into this genus. Dermatosorus eriocauli (Clinton) Whitehead & Thirumalachar is considered to be a member of the genus Moesziomyces (Vanky, 1986). DERMATOSORUS

Sawada in Ling, Mycologia41: 267

(1949)·

Zundelula Thirumalachar & Narasimhan, Sydowia 6: 409 (1952).

Type species: Dermatosorus eleocharidis Sawada, on Eleocharis dulcis Trin. Sori in ovaries, covered by a peridium which later ruptures irregularly, revealing the dark mass of spore balls. Spore balls composed of numerous fertile spores, embedded in a pseudoparenchymatous tissue, and a cortex of sterile cells. Spores dark, medium-sized. Germination of the Ustilago type. The formation and maturation of spore balls are also very interesting and probably unique for this genus. They are produced successively from the columella, and ripen gradually from their distal part. The four known species of Dermatosorus are parasites on Cyperaceae: Bulbostylis, Eleocharis, Fimbristylis, Scirpus, known from E. & S. Asia (Taiwan, India) and Australia.

KEY TO DERMA TOSORUS SPECIES

Cortex of spore balls many-layered, composed of smooth-walled, firmly united sterile cells forming a pseudoparenchymatous tissue. On Eleocharis . . D. eleocharidis 1. Cortex few-layered, composed of loosely united, reticulate-walled sterile cells, not forming a pseudoparen2 chymatous tissue . 2. Spore balls 125-200 ftm diam. Cortex r-z-layered. Spores 8'5-13 ftm. On Bulbostylis . D. bulbostylidis 2. Spore balls larger (150-600 ftm). Cortex z-j-Iayered. Spores smaller (7-11 ftm) 3 D. fimbristylidis 3. Cells of cortex 10-19 ftm. On Fimbristylis 3. Cells of cortex 8'5-14'5 ftm. On Scirpus supinus D. thirumalacharii 1.

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Dermatosorus ( Ustilaginales)

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K. Vanky DERMATOSORUS ELEOCHARIDIS Sawada in Ling, Mycologia 41: 268 (1949). (Figs 1-4) Type on Eleocharis dulcis Trin., Taiwan, Kangshan, Kao-hsiung, 10. iv. 1919, Y. Shimada (BPI I). Sori in scattered ovaries, subglobose, 2-2'5 mm diam, at first covered by a firm, thick, black membrane (' peridium') composed of the ovary wall and a delicate layer of hyphae, which later ruptures irregularly, revealing an aggregate of dark spore balls. In the centre of the sorus is a well-developed columella, composed of an indurated mass of hyphae and remnants of ovule. Spore balls many-spored, rather permanent, irregularly polyangular, ovoidal or rarely subglobose, deep brown, opaque, 90-350 x 110-600 /lm, composed of a central mass of spores embedded in a fine, pseudoparenchymatous tissue of small (0'5-1/lm long), polyangular cells, surrounded by a rather permanent cortex. Spore balls differentiate successively from the hyphal initials amassed over the columella, ripening from their distal part. Loosely packed non-sporogenous hyphae surround the spore balls, extending from the columella to just inside the ovary wall. Sporulation ceases with senescence of the spike of the host. Liberated spore balls bear remnants of non-sporogenous hyphae on their surfaces. Spores loosely united, globose to ovoid, 6-11 /lm diam, reddish-brown; wall smooth, ca 1 /lm thick. Cortex of the spore balls rather permanent, 15-75/lm thick, consisting of several layers of dark reddish-brown, sterile cells, 3-6'5/lm diam, with 0'5-1 /lm thick wall, firmly united, forming a pseudoparenchymatous tissue. Infection local, floral infection. On Cyperaceae: Eleocharis spp., such as E. dulcis Trin., and E. philippinensis Svenson, in Far East (Taiwan), and Australia.

Dermatosorus bulbostylidis (Thirum. & Pavgi) Vanky, comb. nov. Zundelula bulbostylidis Thirumalachar & Pavgi, Sydowia 20: 24 (1967). Type on Bulbostylis capillaris Kunth, India, Varanasi. 19.X.1953, M.S. Pavgi 1241. Sori in scattered ovaries forming spherical-ovate, bullate, dirty grey bodies of f : 5-2 mm diam,

covered by a thick peridium composed of ovary wall and mycelia, which ruptures irregularly to expose the black mass of spore balls. Spore balls rather permanent, irregularly globoid, 125-160 x 150-19° usix, opaque, composed of an outer sheath of sterile cells and an inner mass of spores embedded in a pseudoparenchymatous tissue. Spores globose, subglobose to ovoid, 8'5-13/lm, cinnamon brown; wall smooth, medium thick. Cortex r-z-layered, composed of globose, subglobose to ovoid, 8'5-18'5/lm, cinnamon brown sterile cells possessing thick, reticulate wall. Pseudoparenchymatous tissue between the spores composed of minute, polygonal, pale yellow, sterile cells, up to 1 /lm diam. (Description taken from the original.) On Cyperaceae: Bulbostylis capillaris Kunth, known only from the type locality. (It is not known where the type is deposited.) DERMATOSORUS FIMBRISTYLIDIS (Thirum. & Naras.) Langdon, Trans. Br. mycol. Soc. 68: 450 (1977)· (Figs 5, 6) Zundelulafimbristylidis Thirumalachar & Narasimhan, Sydowia 6: 410 (1952). Type on Fimbristylis sp., India, Patna, 12.xii.1951, M. J. Narasimhan (BPI!; IMI!). Sori in scattered ovaries, forming spherical bullate bodies, l' 5-3 mm diam, enveloped by an outer, thick ovary wall and an inner, thin fungal peridium. Spore balls subglobose to rounded polyangularly irregular, 300-450 x 450-570 /lm, cum posed of numerous spores embedded in a pseudoparenchymatous tissue of sterile cells, surrounded by a cortex. Spores globose to subglobose, 7'5-10'5/lm, yellowish-brown, when dispersed appearing reticulate due to the remnants of the pseudoparenchymatous tissue adhering to the spore surface. Cortex 2-3 layered, composed of globose to subglobose, 10-15 (-19) /lm diam, chestnut-brown, fragile, thick-walled sterile cells, with reticulate wall. Pseudoparenchymatous tissue around the spores composed of thin-walled, small, fragile, polyangular, yellowish-brown sterile cells. Spore germination (Thirumalachar & Narasimhan, 1952) by a four-celled promycelium bearing lateral

Figs 1-4. Dermatosorus eleocharidis. Fig. 1. Sori in scattered ovaries of Eleocharis philippinensis Svenson (Australia, Queensland, near Ipswich, 20. ii. 1975, R. F. N. Langdon, HUV 7179). Fig. 2. L.S. of a young sorus, Fig. 3. Part of a young sorus (L.S.), with spore balls in different stages of maturation. a = remnants of the style, b = sorus membrane, c = mature spore balls, d = immature spore balls, e = non-sporogenous hyphae, f = columella. (Figs 2 and 3 from Langdon, 1977.) Fig. 4. Part of a spore ball (T.S.) showing the cortex of sterile cells, and the spores embedded in a pseudoparenchymatous tissue of very small sterile cells.

Dermatosorus (Ustilaginales)

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I

lmm

~

IOmm

5 Fig. 5. Dermatosorusfimbristylidis on Fimbristylis sp. (Type). Sori in scattered ovaries. A sorus, partly without sorus membrane, showing the spore balls, and a healthy nutlet. Fig. 6. Spores of the Dermatosorus fimbristylidis (Type). On their surface with remnants of the pseudoparenchymatous tissue of sterile cells, appearing as a fine reticulum.

and terminal, hyaline sporidia of 2'5 x 4-6 /lm diam. On Cyperaceae: Fimbristylis sp., known only from the type collection. Dermatosorus thirumalacharii (Pavgi & Giri) Vanky, comb. nov. Zundelula thirumalacharii Pavgi & Giri, Mycopath. Mycol. Appl. 28: 143 (1966). Type on Scirpus supinus L., India, Varanasi, 10. xii. 1963, M. S. Pavgi (321) & B. K. Giri. Sori in scattered ovaries forming spherical-ovate, bullate, dull greyish-brown bodies, 1-2 mm diam, covered by a thick membrane which ruptures irregularly liberating the spore balls. Spore balls globoid, 145-380 x 220-665 psi», opaque, rather permanent, composed of a cortex of sterile cells, and an inner core of spores dispersed in a fine pseudoparenchymatous tissue. Spores globose, subglobose to ovoid, 7'2-10 x 8·6-10·8 /lm, light olive brown; wall smooth, medium thick. Cortex 2-3-layered, composed of globose to ovoid, 8.6-13 x 11'5-14'5 /lm, deep cinnamon brown sterile cells, with thick, reticulate wall. Pseudoparenchymatous tissue (' dermata ') composed of

yellowish-brown, polygonal, thin-walled cells, measuring 0'6-1'2/lm diam. (Description taken from the original.) Spore germination (Pavgi & Giri, 1966; Singh & Pavgi, 1977) without rest period, resulting in a four-celled promycelium, producing lateral and terminal, haploid, hyaline, ovoid sporidia, measuring 2'5-3 x 5-7 pst». Infection of the host plant (Singh & Pavgi, 1970) is a local, floral infection. Field observations indicated that fresh infection continued to occur progressively in the spikelets along the waterline through the floating sporidia from germinating teliospores. On Cyperaceae: Scirpus supinus L., known only from the type locality. I have been unable to secure material of this species for study, but its description and illustrations left no doubt that it is a member of the genus Dermatosorus. DERMA TOSORUS AND MOESZIOMYCES

The genus Moesziomyces was erected by Vanky (1977) to accommodate a peculiar smut, Tolyposporium bullatum (Schroter) Schroter, on Echinochloa crus-galli (L.) Beauv., and some related,

K. Vanky graminicolous smuts. Recently, the genus was revised and its description completed (Vanky, 1986). Moesziomyces is characterized by sori in scattered ovaries, without columella. Spores are in many-spored spore balls, rather firmly agglutinated and mixed with sterile cells. Germination is of the Ustilago type. Two species were recognized: M. bullatus (Schroter) Vanky, on different Gramineae (Echinochloa, Leersia, Paspalum, Pennisetum), and M. eriocauli (G. W. Clinton) Vanky, on Eriocaulaceae (Eriocaulon articulatum (Huds.) Morong). Common to both Dermatosorus and Moesziomyces are the sori in scattered ovaries, the manyspored, rather permanent spore balls composed of spores and sterile cells, and the Ustilago type of germination. Dermatosorus differs from Moesziomyces, i.a., by the peculiar manner of spore ball formation and maturation (produced successively from the columella and ripening from their distal part), by the sorus structure (La. presence of a columella), and by the structure of the spore balls (presence of a cortex of sterile cells in Dermatosorus). I remember the late Professor J. A. Nannfeldt (Uppsala, Sweden) with gratitude, for his critical reading of the manuscript. I am grateful to Professor R. F. N. Langdon (Queensland, Aus-

tralia) for permission to reproduce some of his pictures, and to Professor F.Oberwinkler (Tiibingen, Germany) for reading the manuscript. I am very much obliged to the Directors and Curators of the Herbaria in BPI and IMI for lending me types and other specimens. REFERENCES

LANGDON, R. F. N. (1977). Dermatosorus and Zundelula (Ustilaginales). Transactions of the British Mycological Society 68, 447-450. LING, L. (1949). A second contribution to the knowledge of the Ustilaginales of China. Mycologia 41, 252-269. PAVGI, M. S. & GIRl, B. K. (1966). A new species of Zundelula from India. Mycopathologia et Mycologia Applicata 28, 141-144. SINGH, L. & PAVGI, M. S. (1970). Secondary host infection by Zundelula thirumalacharii. Science and Culture 36, 177-179. SINGH, L. & PAVGI, M. S. (1977). Te1iospore germination and nuclear behaviour of Zundelula thirumalacharii. Sydowia 29, 10-14. THIRUMALACHAR, M. J. & NARASIMHAN, M. J. (1952). Zundelula, a new genus of smuts. Sydowia 6, 407-411. THIRUMALACHAR, M. J. & PAVGI, M. S. (1967). Notes on some Indian Ustilaginae - IX. Sydowia 20, 21-27: VANKY, K. (1977). Moesziomyces, a new genus of Ustilaginales. Botaniska Notiser 130, 131-135. VANKY, K. (1986). The genus Moesziomyces (Ustilaginales). Nordic Journal of Botany 6, 67-73.

(Received for publication

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December 1986)

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