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The genus Phyllachora from Australia. Observations on P. bella from Syzygium paniculatum and P. melaspilea from Scolopia braunii
Mycol. Res.
97 (12): 1437-1440 (1993)
1437
Printed in Great Britain
The genus Phyllachora from Australia. Observations on P. bella from Syzygium paniculatum and P. melaspilea from Scolopia braunii
CERIDWEN A. PEARCE AND KEVIN D. HYDE"" Division of Plant Protection, Queensland Department of Primary Industries, Mareeba, Qld 4880, Australia
Phyl1achora bel1a and P. melaspilea are redescribed and illustrated with differential interference micrographs.
Phyllachora bella Syd., a typical Phyllachora causing black shiny tar spots on senescent leaves, was described from Syzygium paniculatum Gaertner (as Eugenia australis WendL) from Sydney Royal National Park (Sydow, 1937 a). A second species, P. melaspilea Syd., also causing tar spots, was described from senescent leaves of Scolopia braunii (Klotzsch) Sleumer from Port Macquarie (Sydow, 1937 b). Sydow (1937a, b) did not illustrate either species, although Batista (1958) illustrated P. melaspilea with line drawings. In the course of our studies on Australian Phyllachora species we have studied the holotypes of both these taxa and in this paper they are redescribed and illustrated with differential interference micrographs.
continuous with the clypeus (Fig. 4). Asci and paraphyses extend from the base of the ascoma. Fine, hyaline periphyses line the neck (Fig. 5). Paraphyses numerous, not constricted at septa, up to 2'5!-lm diam., no branching seen. Asci 82-142'5 x 6-12!-lm (x= 109 x 9'2 !-lm, n = 25), 8-spored, cylindrical, long to narrow pedunculate, thick-walled, unituncate, tapering to a rounded apex (Figs 6, 7), with a small apical structure, up to 2!-lm diam., I-I'5 ~ wide, non reactive with Melzer's reagent or I % Nigrosin (Fig. 8). Ascospores 9-12 x 4'5--6'5 ~, (x = 10'5 x 5'3 !-lm, n = 50), uniseriate, often oblique, ellipsoidal or oval, often wide at the equator, with acute poles, hyaline, unicellular, with a thin mucilaginous envelope (Figs 9-11).
TAXONOMY
Host species: Syzygium paniculatum.
Phyllachora bella Syd., Annales Mycologici 35, 30 (1937) (Figs 1-11)
Known distribution: Australia.
Leaf spots 455-1950 X 286-988 ~ (x = 750 x 529 !-lm, n = 10), shiny, black, roughly circular, raised, low hemispherical with a flattened apex, often coalescing, occurring as very numerous (50 + in specimens examined) tar spots in a roughly circular region, on one side of the leaf surface only. A fine dark-brown band of discoloured tissue surrounds each leafspot (Figs L 3).
Material examined: Australia: New South Wales, Sydney, Royal National Park on senescent leaf material of Syzygium paniculatum (as Eugenia australis Wendl.), 1937, L. R. Fraser, DAR 3537 (holotype).
Anamorph: Not seen. Teleomorph: Ascomata immersed in the mesophyll, 180-212 !-lm diam., 132-177!-lm high, subglobose to ellipsoidal, with a shallow conical apex fonning the neck (Fig. 2). An amorphous layer of dark-brown melanised palisade and epidennal cells around the neck fonns the clypeus. This sometimes extends into the mesophyll, encircling the ascomata, but not involving the lower palisade or epidennal leaf cells. Upper wall difficult to distinguish from melanised clypeus. Lateral and lower walls 30-37'5 !-lm thick, composed of an inner layer 5-12'5 !-lm thick, of thin-walled, flattened, hyaline fungal cells, merging with the brown amorphous outer layer, up to 25 !-lm thick, and • Present address: Department of Botany. University of Hong Kong, Pokfulam Road, Hong Kong.
Phyllachora bella occurs on Syzygium paniculatum and is only known from the holotype. The specimen was examined by Batista (1958), who gave slightly larger measurements than those of Sydow (1937a); our measurements are similar to those of Batista (1958). We have been unable to trace any records of other Phyllachora species on Syzygium in Australia, although a Phyllachora sp. on Eugenia sp. is held in BRIP (Alcorn, personal communication). Recently, Pearce & Hyde (1993) described Ophiodothella syzygii from Syzygium suborbiculare Benth. from north Queensland. This fungus has a reduced clypeus and scolecospores.
Phyllachora melaspilea Syd., Annales Mycologici 36, 352 (Figs 12-19) (1937)
Leaf spots: 1'7-2-6 x 1'75-2'5 mm (x= 2'4 x 2'1 mm, n = 10), large, black, shiny, roughly circular lesions, usually solitary, sometimes coaleScing, only slightly raised above the leaf surface, occurring on both sides of the leaf tissue and
The genus Phyllachora from Australia
Figs 1-11. For captions see opposite.
1438
C. A. Pearce and K. D. Hyde
1439
Figs 12-19. Differential interference micrographs (except 12) of Phyllachora melaspilea. Fig. 12. Leafspots on leaves of Scolopia braunii. Ascomata found predominantly spreading along leaf veins. Fig. 13. Vertical section through immersed ascoma. Fig. 14. Ostiole. Periphyses line the neck. Fig. 15. Cells of lateral wall. Fig. 16. Asci. Paraphyses are enveloped in gelatinous matrix. Figs 17-19. Ascospores with slight shape variation illustrated. Scale bars: Fig. 12 (1 mm); Fig. 13 (50 lim); Figs 14-19 (10 lim).
Figs 1-11. Phyllachora bella. Figs 1, 3. Leaf spots on leaves of Syzygium paniculatum. Figs 2, 4-11. Differential interference micrographs of P. bella. Fig. 2. Vertical section through immersed ascoma. Fig. 4. Vertical section through lateral peridiurn wall. Cells are inwardly hyaline, thin-walled and flattened, merging with an outer amorphous, melanised host layer. Fig. 5. Ostiole. Periphyses line the neck. Figs 6, 7. Asci. Fig. 8. Non-reactive apical ring-like structure in the ascal tip. Figs 9-11. Ascospores. Note residual mucilaginous envelope in Fig. 9. Scale bars: Fig. 1 (2 mm); Fig. 2 (50 Ilm); Fig. 3 (200 lim); Figs 4-7 (10 Ilffi); Figs &-11 (5 Ilm).
1440
The genus Phyllachora from Australia surrounded by a narrow area of yellow-brown degenerated leaf tissue. Ascomata found predominantly spreading along leaf veins, as irregularly arranged, high hemispherical, roughly circular, coalescing, black, shiny fruiting structures, forming a narrow leaf spot up to 7 mm long, and 2 mm wide (Fig. 12). Ostiole indistinct.
Anamorph: Not seen. Teleomorph: Ascomata immersed deep in the mesophyll and palisade cells, 280-305 \.lm diam., 177-245 lJ.ffi high and subglobose (Fig. 13). Clypeus 20-60 lJ.ffi thick, composed of a brown-black, melanized layer of epidermal and palisade cells and fungal hyphae, beneath the host cuticle. Upper wall approx 7'5 \.lm thick and difficult to distinguish as it merges with the clypeus. Lateral and lower wall, up to 15 lJ.ffi thick, comprising hyaline, thin-walled, flattened fungal cells, merging with compressed host tissue (Fig. 15), Ostiole central, circular, and lined with thin-walled, hyaline periphyses (Fig. 14). Asci and paraphyses surrounded by a gelatinous matrix developing from the base and lower sides of the ascoma. Paraphyses hyaline, not constricted at septa, up to 2'5 \.lm wide, slightly longer than asci, with some branching seen. Asci 65-95 x 12'5-20 lJ.ffi (x = 77'2 x 15'5 \.lm, n = 25), 8-spored, clavate, short pedunculate, thin-walled, unitunicate, tapering to a rounded apex, with no apical structures (Fig. 16). Ascospores 15-20 x 7'5-10 lJ.ffi (x = 17'6 x 8'4 \.lm, n = 50), biseriate, thin-walled, hyaline, ellipsoidal with acute poles, sometimes slightly inaequilateral (Figs 17-19), Host species: Scolopia braunii. Known distribution: Australia: New South Wales. (Accepted 28 April 1993)
Material examined: Australia: New South Wales, Port Macquarie, on 1935, L. R. Fraser,
senescent leaf material of Sealapia braunii, DAR 3541 (holotype).
Phyllachora melaspilea was described from senescent leaves of Scolopia braunii from New South Wales (Sydow, 1937 b) and is also only known from the holotype, Batista (1958) reexamined the holotype and provided a description in Portuguese and an illustration. We can find no other records of other Phyllachora species on this host in Australia. Our measurements are slightly larger than those of Sydow (1937 b) and Batista (1958). We would like to thank the Northern Australian Quarantine Strategy and Australian Quarantine and Inspection Service for funding the research. John Clarkson is also thanked for discussions regarding botanical specimens. Thanks are extended to the curators of DAR for loan of material of the fungus examined in this study.
REFERENCES Batista, A. C. (1958). Alguns Dothideaceae e PhyJlachoraceae estudados em Pernambuco. Revista de Biologia 1, 299-312. Sydow, H. (1937a). Neue oder bemerkenswerte Australische micromyceten. 1. Annales Mycologici 35, 22-52. Sydow, H. (1937 b). Neue oder bemerkenswerte Australische Micromyceten. II. Annales Mycologici 35,350-361. Pearce, C. A. & Hyde, K. D. (1993). The genus Ophiodothella from Australia. Mycological Research 97, 1272-1276.
97 (12): 1437-1440 (1993)
1437
Printed in Great Britain
The genus Phyllachora from Australia. Observations on P. bella from Syzygium paniculatum and P. melaspilea from Scolopia braunii
CERIDWEN A. PEARCE AND KEVIN D. HYDE"" Division of Plant Protection, Queensland Department of Primary Industries, Mareeba, Qld 4880, Australia
Phyl1achora bel1a and P. melaspilea are redescribed and illustrated with differential interference micrographs.
Phyllachora bella Syd., a typical Phyllachora causing black shiny tar spots on senescent leaves, was described from Syzygium paniculatum Gaertner (as Eugenia australis WendL) from Sydney Royal National Park (Sydow, 1937 a). A second species, P. melaspilea Syd., also causing tar spots, was described from senescent leaves of Scolopia braunii (Klotzsch) Sleumer from Port Macquarie (Sydow, 1937 b). Sydow (1937a, b) did not illustrate either species, although Batista (1958) illustrated P. melaspilea with line drawings. In the course of our studies on Australian Phyllachora species we have studied the holotypes of both these taxa and in this paper they are redescribed and illustrated with differential interference micrographs.
continuous with the clypeus (Fig. 4). Asci and paraphyses extend from the base of the ascoma. Fine, hyaline periphyses line the neck (Fig. 5). Paraphyses numerous, not constricted at septa, up to 2'5!-lm diam., no branching seen. Asci 82-142'5 x 6-12!-lm (x= 109 x 9'2 !-lm, n = 25), 8-spored, cylindrical, long to narrow pedunculate, thick-walled, unituncate, tapering to a rounded apex (Figs 6, 7), with a small apical structure, up to 2!-lm diam., I-I'5 ~ wide, non reactive with Melzer's reagent or I % Nigrosin (Fig. 8). Ascospores 9-12 x 4'5--6'5 ~, (x = 10'5 x 5'3 !-lm, n = 50), uniseriate, often oblique, ellipsoidal or oval, often wide at the equator, with acute poles, hyaline, unicellular, with a thin mucilaginous envelope (Figs 9-11).
TAXONOMY
Host species: Syzygium paniculatum.
Phyllachora bella Syd., Annales Mycologici 35, 30 (1937) (Figs 1-11)
Known distribution: Australia.
Leaf spots 455-1950 X 286-988 ~ (x = 750 x 529 !-lm, n = 10), shiny, black, roughly circular, raised, low hemispherical with a flattened apex, often coalescing, occurring as very numerous (50 + in specimens examined) tar spots in a roughly circular region, on one side of the leaf surface only. A fine dark-brown band of discoloured tissue surrounds each leafspot (Figs L 3).
Material examined: Australia: New South Wales, Sydney, Royal National Park on senescent leaf material of Syzygium paniculatum (as Eugenia australis Wendl.), 1937, L. R. Fraser, DAR 3537 (holotype).
Anamorph: Not seen. Teleomorph: Ascomata immersed in the mesophyll, 180-212 !-lm diam., 132-177!-lm high, subglobose to ellipsoidal, with a shallow conical apex fonning the neck (Fig. 2). An amorphous layer of dark-brown melanised palisade and epidennal cells around the neck fonns the clypeus. This sometimes extends into the mesophyll, encircling the ascomata, but not involving the lower palisade or epidennal leaf cells. Upper wall difficult to distinguish from melanised clypeus. Lateral and lower walls 30-37'5 !-lm thick, composed of an inner layer 5-12'5 !-lm thick, of thin-walled, flattened, hyaline fungal cells, merging with the brown amorphous outer layer, up to 25 !-lm thick, and • Present address: Department of Botany. University of Hong Kong, Pokfulam Road, Hong Kong.
Phyllachora bella occurs on Syzygium paniculatum and is only known from the holotype. The specimen was examined by Batista (1958), who gave slightly larger measurements than those of Sydow (1937a); our measurements are similar to those of Batista (1958). We have been unable to trace any records of other Phyllachora species on Syzygium in Australia, although a Phyllachora sp. on Eugenia sp. is held in BRIP (Alcorn, personal communication). Recently, Pearce & Hyde (1993) described Ophiodothella syzygii from Syzygium suborbiculare Benth. from north Queensland. This fungus has a reduced clypeus and scolecospores.
Phyllachora melaspilea Syd., Annales Mycologici 36, 352 (Figs 12-19) (1937)
Leaf spots: 1'7-2-6 x 1'75-2'5 mm (x= 2'4 x 2'1 mm, n = 10), large, black, shiny, roughly circular lesions, usually solitary, sometimes coaleScing, only slightly raised above the leaf surface, occurring on both sides of the leaf tissue and
The genus Phyllachora from Australia
Figs 1-11. For captions see opposite.
1438
C. A. Pearce and K. D. Hyde
1439
Figs 12-19. Differential interference micrographs (except 12) of Phyllachora melaspilea. Fig. 12. Leafspots on leaves of Scolopia braunii. Ascomata found predominantly spreading along leaf veins. Fig. 13. Vertical section through immersed ascoma. Fig. 14. Ostiole. Periphyses line the neck. Fig. 15. Cells of lateral wall. Fig. 16. Asci. Paraphyses are enveloped in gelatinous matrix. Figs 17-19. Ascospores with slight shape variation illustrated. Scale bars: Fig. 12 (1 mm); Fig. 13 (50 lim); Figs 14-19 (10 lim).
Figs 1-11. Phyllachora bella. Figs 1, 3. Leaf spots on leaves of Syzygium paniculatum. Figs 2, 4-11. Differential interference micrographs of P. bella. Fig. 2. Vertical section through immersed ascoma. Fig. 4. Vertical section through lateral peridiurn wall. Cells are inwardly hyaline, thin-walled and flattened, merging with an outer amorphous, melanised host layer. Fig. 5. Ostiole. Periphyses line the neck. Figs 6, 7. Asci. Fig. 8. Non-reactive apical ring-like structure in the ascal tip. Figs 9-11. Ascospores. Note residual mucilaginous envelope in Fig. 9. Scale bars: Fig. 1 (2 mm); Fig. 2 (50 Ilm); Fig. 3 (200 lim); Figs 4-7 (10 Ilffi); Figs &-11 (5 Ilm).
1440
The genus Phyllachora from Australia surrounded by a narrow area of yellow-brown degenerated leaf tissue. Ascomata found predominantly spreading along leaf veins, as irregularly arranged, high hemispherical, roughly circular, coalescing, black, shiny fruiting structures, forming a narrow leaf spot up to 7 mm long, and 2 mm wide (Fig. 12). Ostiole indistinct.
Anamorph: Not seen. Teleomorph: Ascomata immersed deep in the mesophyll and palisade cells, 280-305 \.lm diam., 177-245 lJ.ffi high and subglobose (Fig. 13). Clypeus 20-60 lJ.ffi thick, composed of a brown-black, melanized layer of epidermal and palisade cells and fungal hyphae, beneath the host cuticle. Upper wall approx 7'5 \.lm thick and difficult to distinguish as it merges with the clypeus. Lateral and lower wall, up to 15 lJ.ffi thick, comprising hyaline, thin-walled, flattened fungal cells, merging with compressed host tissue (Fig. 15), Ostiole central, circular, and lined with thin-walled, hyaline periphyses (Fig. 14). Asci and paraphyses surrounded by a gelatinous matrix developing from the base and lower sides of the ascoma. Paraphyses hyaline, not constricted at septa, up to 2'5 \.lm wide, slightly longer than asci, with some branching seen. Asci 65-95 x 12'5-20 lJ.ffi (x = 77'2 x 15'5 \.lm, n = 25), 8-spored, clavate, short pedunculate, thin-walled, unitunicate, tapering to a rounded apex, with no apical structures (Fig. 16). Ascospores 15-20 x 7'5-10 lJ.ffi (x = 17'6 x 8'4 \.lm, n = 50), biseriate, thin-walled, hyaline, ellipsoidal with acute poles, sometimes slightly inaequilateral (Figs 17-19), Host species: Scolopia braunii. Known distribution: Australia: New South Wales. (Accepted 28 April 1993)
Material examined: Australia: New South Wales, Port Macquarie, on 1935, L. R. Fraser,
senescent leaf material of Sealapia braunii, DAR 3541 (holotype).
Phyllachora melaspilea was described from senescent leaves of Scolopia braunii from New South Wales (Sydow, 1937 b) and is also only known from the holotype, Batista (1958) reexamined the holotype and provided a description in Portuguese and an illustration. We can find no other records of other Phyllachora species on this host in Australia. Our measurements are slightly larger than those of Sydow (1937 b) and Batista (1958). We would like to thank the Northern Australian Quarantine Strategy and Australian Quarantine and Inspection Service for funding the research. John Clarkson is also thanked for discussions regarding botanical specimens. Thanks are extended to the curators of DAR for loan of material of the fungus examined in this study.
REFERENCES Batista, A. C. (1958). Alguns Dothideaceae e PhyJlachoraceae estudados em Pernambuco. Revista de Biologia 1, 299-312. Sydow, H. (1937a). Neue oder bemerkenswerte Australische micromyceten. 1. Annales Mycologici 35, 22-52. Sydow, H. (1937 b). Neue oder bemerkenswerte Australische Micromyceten. II. Annales Mycologici 35,350-361. Pearce, C. A. & Hyde, K. D. (1993). The genus Ophiodothella from Australia. Mycological Research 97, 1272-1276.