- Email: [email protected]
Two nematode-trapping hyphomycetes, duddingtonia flagrans gen. et comb.nov. and monagrosporium mutabilis sp.nov.
Notes and Brief Articles Leaf spots amphigenous, numerous, scattered, pale brown, with a purplish brown border more prominent on the upper surface, 1-4 mm across, delimited by veins. Pycnidia mostly epiphyllous, sparse, immersed, globose, (70-) 140-180 pm diam, with a rounded ostiole 30-40 pm wide. Pycnidial wall continuous, 3-4 cells thick, outermost cell layer light brown, inner layers hyaline. Conidiophores formed from the innermost layer of the pycnidial wall, hyaline, simple, non-septate, cylindrical, straight, 3-7 x 4-S usi». Pycnidiospores (blastospores) hyaline, cylindrical or obclavate-subulate, straight or curved, (40-) SO-80XI'S-2'spm, (2) 3-S septate. On living leaves of Guizotia abyssinicae Cass., Holetta, Ethiopia, IS. viii. 1967, colI. D. Yirgou, IMI 129949 type. This is the first record of a Septoria on Guirotia. I am grateful to Mr P. Basu and Mr F. C. Deighton for preparing the Latin diagnoses. REFERENCES
CASTELLANI, E. (1943). Monochaetiella hyparrheniae nobis n.sp, Nuooo G. bot. ital. (1942), 49,48 7. KANDASWAMY, M. & SUNDARAM, N. V. (1956). An interesting disease of Themeda tremula. Indian Phytopath. 9, 202-203. E. PUNITHALINGAM,
Commonwealth Mycological Institute, Kew
Two
NEMATODE-TRAPPING HYPHOMYCETES, DUDDINGTONIA FLAGRANS GEN. ET COMB.NOV. AND MONACROSPORIUM MUTABILIS SP.NOV.
Duddingtonia R. C. Cooke, gen.nov. Fungi imperfecti, hyphomycetes, didymospori. Coloniae effusae, pallide roseae. Mycelium ex hyphis septatis, hyalinis, ramosis, levibus compositum. Conidiophora singula ex lateribus hypharum oriunda, erecta, hyalina, Ievia, Conidia singula in apice conidiophori oriunda, dein in capitulo gesta, obconica vel ellipsiodea, levia, hyalina, uniseptata, plerumque per septum in duas partes circa aequas diviso. Illaqueans et consumens vermiculos nematodeos. Species generis typica: Duddingtonia jlagrans (Duddington) R. C. Cooke.
In pure culture on cornmeal agar, colonies effused, white to pale pink. Mycelium composed of septate, hyaline, branched hyphae with little aerial growth. Conidiophores simple, septate, erect, straight, elongating or enlarging slightly at the tip by repeated subapical growth, hyaline and smoothwalled. Conidia arise singly as blown out ends of conidiophores; after the first conidium has been formed a new growing point appears to one side of it or slightly below it and a second conidium is formed here, displacing the first one laterally, this process being repeated several times; conidia obconical to ellipsoidal, smooth-walled, r-septate, the proximal cell being basally broadly truncate and of about equal size to the distal cell, hyaline. Type species Duddingtoniajlagrans (Duddington) R. C. Cooke. In describing T richothecium jlagrans, Duddington (1950) pointed out that the shape of its conidia and the manner of their development was different Trans. Br. mycol. Soc. 53 (2), (1969). Printed in Great Britain
316
Transactions British Mycological Society
from that found in Arthrobotrys Corda and considered that it bore a close resemblance to Trichothecium Link ex Fr. However, T. flagrans lacks the catenulate conidial clusters of the latter genus and instead forms a capitate head of closely crowded spores. This species appears not to have been found again since its first description and, unfortunately, the type culture has lost the ability to form conidia. The following description is based on an isolate from soil, Rive1in Dam, Yorks,] anuary 1969, R. C. Cooke, 2 NH 8. Although conidia of this isolate are slightly larger than those described by Duddington there seems to be no doubt that it is the same species.
20 pm
Fig.
I.
Duddingtonia j/agrans, conidiophores and conidia at various stages of development and an intercalary chlamydospore.
Duddingtonia flagrans (Duddington) R. C. Cooke comb. nov. (Fig. I) == Trichothecium flagrans Duddington, in Trans. Br. mycol. Soc. 32, 287, 1950 (basionym)
In pure culture on cornmeal agar colonies are effused, almost smooth, with few aerial hyphae. The mycelium is of branched, septate, smoothwalled hyphae 3-5 pm in diameter. On nematode-infested agar, adhesive three-dimensional hyphal networks are formed in which nematodes are captured. Conidiophores arise singly and are erect, straight, unbranched, and up to 150 pm long. Conidia arise singly as blown-out ends of the conidiophore. After the first conidium has been produced a new growing point is formed to one side of and slightly below it and a second conidium Trans. Br, mycol. Soc. 53 (2), (1969). Printed in Great Britain
Notes and Brief Articles
317
is produced here which displaces the first one to a lateral position. This process may be repeated several times so that ultimately conidiophores may bear up to six closely grouped conidia. The conidiophore increases slightly in length during this process and its apex becomes somewhat expanded (Fig. I). Conidia are obconical to ellipsoidal, I-septate, the proximal cell being broadly truncate. They are smooth-walled, 25-50 x IO-I5)l,m. Detached conidia leave behind flattened scars on the shoulder of the conidiophore. Intercalary chlamydospores are formed abundantly. These are yellow, usually spherical and up to 30 flm in external diameter.
A
B
20l' m
Fig. 2. Monacrosporium mutabilis. A, Adhesive lateral branches and a trapped nematode; B, conidia from nematode-infested cornmeal agar; C, conidia from a pure culture on cornmeal agar; D, malformed conidia from a pure culture.
Trans. Br. mycol. Soc. 53 (2), (1969). Printed in Great Britain
318
Transactions British Mycological Society
This genus is notable in that the point of conidial insertion is very wide, being usually as wide as the conidiophore itself. Conidia might, therefore, be termed murogenous. Although murogenous and blastogenous conidia may not always be readily distinguishable (Luttrell, 1963) in this case it is clear that the conidia are radulaspores. Monacrosporium mutabilis R. C. Cooke sp.nov, Mycelium hyalinum, hyphae septatae, ramosae, praesentibus vermiculis nematodeis bullas tenaces globosas proferentibus. Hyphae fertiles erectae, septatae, in apice unicum conidium gerentes. Conidia hyalina, ellipsoidea, 3-4 plerumque 4-septata, 37'5-50 #m longa, 12'5-15 #m lata. Illaqueans et consumens vermiculos nematodeos in terra prope Nafanua, Western Samoa. Typus culturus IMI 138,221 est.
This species was isolated from soil from Nafanua, Western Samoa. On nematode-infested cornmeal agar it captured nematodes on modified lateral hyphal branches. These usually consisted of three cells, the terminal one being swollen to form a spherical or subspherical adhesive knob
25p m
Fig. 3. Conidia of knob-forming Monacrosporium species from pure culture on cornmeal agar. A, M. drechsleri; B, M. mammillatum; C, M. ellipsosporum.
about 5 flm in diameter (Fig. 2 A). These lateral hyphae were frequently branched at the base and densely crowded on their parent hyphae. Conidiophores were simple, septate, erect, and bore at their apices single, terminal conidia. Conidia were ellipsoidal, 50-60 flm long, 16-17'5 flm wide, invariably 4-septate, with the median cell markedly larger than the rest (Fig. 2 B). They tapered to a narrowly rounded cell distally and proximally to a narrowly truncate base. In pure culture on cornmeal agar conidia were markedly different in Trans. Br. mycol. Soc. 53 (2), (1969). Printed in Great Britain
Notes and Brief Articles
319
both size and shape from those on the nematode-infested substrate (Fig. 2 C), being 37'S-50 pm long and 12'5-15 pm wide. In addition, about 14 % of conidia were 3-septate. Curved, malformed spores were frequent (Fig. 2 D). Only three species of Monacrosponum which capture nem atodes on consistently stalked, adhesive knobs are known. These are M. ellipsosporum (Drechsler, 1937), M. mammillatum (Dixon, 1952), and M. drechsleri (T arj an, 1961 ). Conidia of these three species from pure cultures on cornmeal agar are shown in Fig. 3. M. mutabilis may be readily distinguished from them on its conidial characters and on its very stout, densely crowded, branched trapping organs. I wish to thank Dr P. G. Long of the South Pacific Regional College of Tropical Agriculture, Alafua, Western Samoa, for a gift of soil samples. REFERENCES
DIXON, S. M. (1952). Predaceous fungi from rotten wood. Trans. Br. mycol. Soc. 35, 144- 148. DRECHSLER, C. (1937)' Some hyphomycetes that prey on free-living terricolous nematodes. Mycologia 29,447-552. DUDDINGTON, C. L. (1950). A new predaceous species of Trichothecium. Trans. Br. mycol. Soc. 32, 284-287. LUTTRELL, E. S. (1963)' Taxonomic criteria in Helminthosporium. Mycologia 55,643-674. TARJAN, A. C. (1961). Gro wth characteristics of Dactylella drechsleri n.sp., an adhesiveknobbed, nematode-trapping hyphomycete from Florida. Mycopath. Mycol. Appl. 14, 136-144. R. C. COOKE,
Botany Department, The University, Sheffield
AsCOSPORE GERMINATION IN PARODIELLA
The ascomycetous genus Parodiella Spegazzini (1880), with P. perisporioides (Berk. & Curt.) Speg. as type, has been taxonomically studied by several workers. It is noteworthy that all the species, without exception, have been collected on legume hosts. This host-parasite relationship is a unique feature of the genus, the nature of which has not been fully understood. Tilak (1963) made a comparative study of five collections on different legume hosts from Bombay (India) and considered these as formae speciales of the type species, following in this respect Muller & Arx (1962) pending further investigations based on cultural and cross-inoculation studies. No conidial state has been recorded for this genus except the report by Petrak (1934) of Scleroparodia leguminosarum Petro These considerations induced the writer to undertake trials on the germination of ascospores of this genus with the ultimate object of obtaining these fungi in culture for a more detailed study of the life-cycle, conidial states, if any , and biology. Critical examination of the literature revealed no report on ascospore germination in this genus, although such germination doubtless occurs in nature. Pretreatment of ascospores with freezing, desiccation and thawing and Tra ns. B r. mycol. Soc. 53 (2), (196g). Printed in Great Britain
CASTELLANI, E. (1943). Monochaetiella hyparrheniae nobis n.sp, Nuooo G. bot. ital. (1942), 49,48 7. KANDASWAMY, M. & SUNDARAM, N. V. (1956). An interesting disease of Themeda tremula. Indian Phytopath. 9, 202-203. E. PUNITHALINGAM,
Commonwealth Mycological Institute, Kew
Two
NEMATODE-TRAPPING HYPHOMYCETES, DUDDINGTONIA FLAGRANS GEN. ET COMB.NOV. AND MONACROSPORIUM MUTABILIS SP.NOV.
Duddingtonia R. C. Cooke, gen.nov. Fungi imperfecti, hyphomycetes, didymospori. Coloniae effusae, pallide roseae. Mycelium ex hyphis septatis, hyalinis, ramosis, levibus compositum. Conidiophora singula ex lateribus hypharum oriunda, erecta, hyalina, Ievia, Conidia singula in apice conidiophori oriunda, dein in capitulo gesta, obconica vel ellipsiodea, levia, hyalina, uniseptata, plerumque per septum in duas partes circa aequas diviso. Illaqueans et consumens vermiculos nematodeos. Species generis typica: Duddingtonia jlagrans (Duddington) R. C. Cooke.
In pure culture on cornmeal agar, colonies effused, white to pale pink. Mycelium composed of septate, hyaline, branched hyphae with little aerial growth. Conidiophores simple, septate, erect, straight, elongating or enlarging slightly at the tip by repeated subapical growth, hyaline and smoothwalled. Conidia arise singly as blown out ends of conidiophores; after the first conidium has been formed a new growing point appears to one side of it or slightly below it and a second conidium is formed here, displacing the first one laterally, this process being repeated several times; conidia obconical to ellipsoidal, smooth-walled, r-septate, the proximal cell being basally broadly truncate and of about equal size to the distal cell, hyaline. Type species Duddingtoniajlagrans (Duddington) R. C. Cooke. In describing T richothecium jlagrans, Duddington (1950) pointed out that the shape of its conidia and the manner of their development was different Trans. Br. mycol. Soc. 53 (2), (1969). Printed in Great Britain
316
Transactions British Mycological Society
from that found in Arthrobotrys Corda and considered that it bore a close resemblance to Trichothecium Link ex Fr. However, T. flagrans lacks the catenulate conidial clusters of the latter genus and instead forms a capitate head of closely crowded spores. This species appears not to have been found again since its first description and, unfortunately, the type culture has lost the ability to form conidia. The following description is based on an isolate from soil, Rive1in Dam, Yorks,] anuary 1969, R. C. Cooke, 2 NH 8. Although conidia of this isolate are slightly larger than those described by Duddington there seems to be no doubt that it is the same species.
20 pm
Fig.
I.
Duddingtonia j/agrans, conidiophores and conidia at various stages of development and an intercalary chlamydospore.
Duddingtonia flagrans (Duddington) R. C. Cooke comb. nov. (Fig. I) == Trichothecium flagrans Duddington, in Trans. Br. mycol. Soc. 32, 287, 1950 (basionym)
In pure culture on cornmeal agar colonies are effused, almost smooth, with few aerial hyphae. The mycelium is of branched, septate, smoothwalled hyphae 3-5 pm in diameter. On nematode-infested agar, adhesive three-dimensional hyphal networks are formed in which nematodes are captured. Conidiophores arise singly and are erect, straight, unbranched, and up to 150 pm long. Conidia arise singly as blown-out ends of the conidiophore. After the first conidium has been produced a new growing point is formed to one side of and slightly below it and a second conidium Trans. Br, mycol. Soc. 53 (2), (1969). Printed in Great Britain
Notes and Brief Articles
317
is produced here which displaces the first one to a lateral position. This process may be repeated several times so that ultimately conidiophores may bear up to six closely grouped conidia. The conidiophore increases slightly in length during this process and its apex becomes somewhat expanded (Fig. I). Conidia are obconical to ellipsoidal, I-septate, the proximal cell being broadly truncate. They are smooth-walled, 25-50 x IO-I5)l,m. Detached conidia leave behind flattened scars on the shoulder of the conidiophore. Intercalary chlamydospores are formed abundantly. These are yellow, usually spherical and up to 30 flm in external diameter.
A
B
20l' m
Fig. 2. Monacrosporium mutabilis. A, Adhesive lateral branches and a trapped nematode; B, conidia from nematode-infested cornmeal agar; C, conidia from a pure culture on cornmeal agar; D, malformed conidia from a pure culture.
Trans. Br. mycol. Soc. 53 (2), (1969). Printed in Great Britain
318
Transactions British Mycological Society
This genus is notable in that the point of conidial insertion is very wide, being usually as wide as the conidiophore itself. Conidia might, therefore, be termed murogenous. Although murogenous and blastogenous conidia may not always be readily distinguishable (Luttrell, 1963) in this case it is clear that the conidia are radulaspores. Monacrosporium mutabilis R. C. Cooke sp.nov, Mycelium hyalinum, hyphae septatae, ramosae, praesentibus vermiculis nematodeis bullas tenaces globosas proferentibus. Hyphae fertiles erectae, septatae, in apice unicum conidium gerentes. Conidia hyalina, ellipsoidea, 3-4 plerumque 4-septata, 37'5-50 #m longa, 12'5-15 #m lata. Illaqueans et consumens vermiculos nematodeos in terra prope Nafanua, Western Samoa. Typus culturus IMI 138,221 est.
This species was isolated from soil from Nafanua, Western Samoa. On nematode-infested cornmeal agar it captured nematodes on modified lateral hyphal branches. These usually consisted of three cells, the terminal one being swollen to form a spherical or subspherical adhesive knob
25p m
Fig. 3. Conidia of knob-forming Monacrosporium species from pure culture on cornmeal agar. A, M. drechsleri; B, M. mammillatum; C, M. ellipsosporum.
about 5 flm in diameter (Fig. 2 A). These lateral hyphae were frequently branched at the base and densely crowded on their parent hyphae. Conidiophores were simple, septate, erect, and bore at their apices single, terminal conidia. Conidia were ellipsoidal, 50-60 flm long, 16-17'5 flm wide, invariably 4-septate, with the median cell markedly larger than the rest (Fig. 2 B). They tapered to a narrowly rounded cell distally and proximally to a narrowly truncate base. In pure culture on cornmeal agar conidia were markedly different in Trans. Br. mycol. Soc. 53 (2), (1969). Printed in Great Britain
Notes and Brief Articles
319
both size and shape from those on the nematode-infested substrate (Fig. 2 C), being 37'S-50 pm long and 12'5-15 pm wide. In addition, about 14 % of conidia were 3-septate. Curved, malformed spores were frequent (Fig. 2 D). Only three species of Monacrosponum which capture nem atodes on consistently stalked, adhesive knobs are known. These are M. ellipsosporum (Drechsler, 1937), M. mammillatum (Dixon, 1952), and M. drechsleri (T arj an, 1961 ). Conidia of these three species from pure cultures on cornmeal agar are shown in Fig. 3. M. mutabilis may be readily distinguished from them on its conidial characters and on its very stout, densely crowded, branched trapping organs. I wish to thank Dr P. G. Long of the South Pacific Regional College of Tropical Agriculture, Alafua, Western Samoa, for a gift of soil samples. REFERENCES
DIXON, S. M. (1952). Predaceous fungi from rotten wood. Trans. Br. mycol. Soc. 35, 144- 148. DRECHSLER, C. (1937)' Some hyphomycetes that prey on free-living terricolous nematodes. Mycologia 29,447-552. DUDDINGTON, C. L. (1950). A new predaceous species of Trichothecium. Trans. Br. mycol. Soc. 32, 284-287. LUTTRELL, E. S. (1963)' Taxonomic criteria in Helminthosporium. Mycologia 55,643-674. TARJAN, A. C. (1961). Gro wth characteristics of Dactylella drechsleri n.sp., an adhesiveknobbed, nematode-trapping hyphomycete from Florida. Mycopath. Mycol. Appl. 14, 136-144. R. C. COOKE,
Botany Department, The University, Sheffield
AsCOSPORE GERMINATION IN PARODIELLA
The ascomycetous genus Parodiella Spegazzini (1880), with P. perisporioides (Berk. & Curt.) Speg. as type, has been taxonomically studied by several workers. It is noteworthy that all the species, without exception, have been collected on legume hosts. This host-parasite relationship is a unique feature of the genus, the nature of which has not been fully understood. Tilak (1963) made a comparative study of five collections on different legume hosts from Bombay (India) and considered these as formae speciales of the type species, following in this respect Muller & Arx (1962) pending further investigations based on cultural and cross-inoculation studies. No conidial state has been recorded for this genus except the report by Petrak (1934) of Scleroparodia leguminosarum Petro These considerations induced the writer to undertake trials on the germination of ascospores of this genus with the ultimate object of obtaining these fungi in culture for a more detailed study of the life-cycle, conidial states, if any , and biology. Critical examination of the literature revealed no report on ascospore germination in this genus, although such germination doubtless occurs in nature. Pretreatment of ascospores with freezing, desiccation and thawing and Tra ns. B r. mycol. Soc. 53 (2), (196g). Printed in Great Britain