Mycol Progress (2012) 11:1–6 DOI 10.1007/s11557-011-0791-9
REVIEW
A new genus of Parmulariaceae from Panama Carlos A. Inácio & Karoline Araúz & Meike Piepenbring
Received: 21 June 2011 / Revised: 3 October 2011 / Accepted: 11 October 2011 / Published online: 11 November 2011 # German Mycological Society and Springer 2011
Abstract During a survey of plant-parasitic microfungi in Panama, a new species in a new genus of Parmulariaceae (Ascomycota), Antoniomyces loranthicola, was found on leaves of Gaiadendron punctatum (Loranthaceae). It is described and illustrated. The new species and the new genus differ morphologically from all other known species and genera known in Parmulariaceae by deep internal stroma and superficial radiating hyphae without appressoria. Keywords Ascomycota . Foliicolous fungi . Mycodiversity . Neotropics . Plant parasitic fungi
Introduction The family Parmulariaceae Ascomycota) belongs to the Dothideomycetes inc. sed., Pezizomycotina (Lumbsch and Huhndorf 2007, 2010; Hibbett et al. 2007). Species of Parmulariaceae are biotrophic, plant-parasitic microfungi characterized by colonies on the surface of living plant tissue, mostly on leaves, and by bitunicate asci with septate ascospores surrounded by septate pseudoparaphyses underC. A. Inácio (*) Departamento de Fitopatologia, Universidade de Brasília, 70910-900 Brasília, DF, Brasil e-mail:
[email protected] K. Araúz Universidad Autónoma de Chiriquí, 0427 David, Chiriquí, Panama
neath a covering stroma which later breaks to expose the hamathecium and the asci. They differ from species of Asterinaceae, which are supposed to be closely related, by upright asci, the presence of pseudoparaphyses, a covering stroma formed by several layers of pigmented cells, and the presence of a hypostroma (internal stroma) formed by fungal hyphae below the fungal colony, i.e. underneath the cuticule, in the epidermis, or in the mesophyll (Inácio and Cannon 2008). Species of Asterinaceae are characterized by the presence of superficial hyphae mostly with appressoria (hyphopodia), whereas in species of Parmulariaceae, superficial hyphae can lack completely or, if they are present, they rarely carry appressoria. Species of Parmulariaceae have been studied during the last years by Sivanesan (1970), Sivanesan and Sinha (1989), Sivanesan et al. (1998), Inácio (2005), Inácio and Cannon (2004, 2008), Inácio and Minter (2002a, b, c, d, e, f, g, h, i), and Inácio et al. (2011). Recent additions of genera include Mintera Inácio & Cannon and Viegasella Inácio & Cannon (Inácio and Cannon 2003). Species of Parmulariaceae have been reported from more than 50 host families (Inácio and Cannon 2008), but not up to now on Loranthaceae. The host of the new species is Gaiadendron punctatum (Ruiz & Pav.) G. Don., Loranthaceae), which is a shrub or small tree parasitic on roots of other plants, 3–6 m high, with simple, coriaceous leaves on erect terete branches (Rizzini 1960). Since 2003, the new species of Parmulariaceae was repeatedly collected on G. punctatum in the province of Chiriquí in Western Panama.
Materials and methods M. Piepenbring Institute for Ecology, Evolution and Diversity, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Str. 13, 60438 Frankfurt/M, Germany
Specimens of the new species on leaves of Gaiadendron punctatum were repeatedly collected at the crest of a mountain chain covered by tropical mountain forest in the
2
Parque Internacional la Amistad (PILA), in the province of Chiriquí, Panama. They were studied with a hand lens in the field and in the laboratory by stereo microscopy and light microscopy. Fungal samples were mounted in squash preparations or sectioned using razor blades or a freezing microtome for anatomical studies, and they are documented by microphotography and drawings. Some samples were stained with lacto-glycerol-cotton blue or glycerol-KOHphloxine B and the slides sealed with nail polish. The amyloid reaction was tested with IKI (iodine–potassium iodide´s reagent I 1%; KI 3%). The size of spores and asci is described based on 50 measurements and presented based on the mean value plus and minus the standard deviation, with extreme values added in parentheses. Specimens are deposited in the Herbario Nacional de Panamá (PMA), the herbarium Coleção Micológica de Referência, Herbário Universidade de Brasília (UB), the Herbarium of the Universidad Autónoma de Chiriquí (U.CH.), and the Botanische Staatssammlung in Munich, Germany (M).
Taxonomy Antoniomyces loranthicola Inácio gen. et sp. nov. Figures 1 and 2 Mycobank: genus MB 563246, species MB 563247 Etymology of the generic name: named for Antônio Inácio, father of the first author and member of Brazilian expeditionary forces in Italy, 1944–45. Etymology of the epithet: named for the family of the host plant, Loranthaceae. Coloniae in foliis, superficiales, nigrae, 1–3 diam., quaeque cum crusta stromatica nigra exteriori, stromatibus,cum 2–5 (−6) ascomatibus, conidiomatibus et stromatibus subepidermalibus, amphigenis, dispersa, raro confluentes. Mycelium exterior e hyphis brunneis, septatis, ramosis, anastomosentibus, sin appressoriis. Mycelium interiore subepidermale, e hyphis hyalines compositum, 2–4 μm crassis, septatis, columnaris 12–50×(7–) 15–35 μm, atro-brunnea, cellulis atro-brunneis, angularis, 4–10 μm, textura angularis composito, postea penetrans penitus mesophyllum. Ascomatibus ellipsoidea ad elongati vel navicularia, infra crustam stromaticam et in cuticulam folii superficialia, in sectio transversa 105–150 μm alta et circa 175–550 μm lata, ascis pseudoparaphysibusque referta. Asci cylindraceo-clavati ad late clavati, crassitunicati, rostrati, (45–) 58–66 (−75)×(13–) 16–21 μm, non caerulescentes in iodo, cum 6- ad 8-sporis induti, uniseriatis vel biseriatis vel pluriseriatis. Ascosporae uniseptatae, cylindraceoellipsoideae vel ellipsoideae, (17–) 21–23 (−24)× 7–9 (−11) μm, pallide brunneae vel brunneae, gelatinosae, laeves vel verrucosae, vagina mucilagina quaeque indutae quae statu licet maturo degenerat.
Mycol Progress (2012) 11:1–6
Type: On leaves of Gaiadendron punctatum (Ruiz & Pav.) G. Don (Loranthaceae). PANAMA. CHIRIQUI: Parque Internacional la Amistad, La Cascada trail, at the second lookout close to the highest point of the trail, alt. approx. 2,340 ma.s.l., 8°54.1′N, 82°37.2′W, 21 August 2010, Piepenbring 4994, T. Hofmann, D. Pitty, S. Rudolph, and G. Steinbeisser (holotype in PMA, isotypes in M 0141261, U.CH.). Symptoms: visible as superficial black, rarely confluent stromatic colonies, few and scattered, on both sides of leaves, mostly epiphyllous, the leaf tissue beneath brown in colour, less visible on the lower side of the leaf; colonies variable in shape, mostly circular or elliptical, each colony with a black stromatic crust (external stroma) of 1–3 mm diam., 2–5 (−6) ascomata, conidiomata, and a subepidermal stroma. External hyphae: growing out from ascomata or stromatic crusts, brown, septate, sinuous, smooth, 2–5 μm diam., with long or short lateral branches often anastomosing with adjacent hyphae of the same colony, without appressoria. Internal stroma: corresponding to an internal layer underneath the epidermis, partially effuse, later penetrating through the mesophyll, eventually connecting the adaxial structures to an ascoma on the abaxial side of the leaf, composed of colourless to pale, branched, sinuous, smooth hyphae, 2–4 μm diam., stromatic columns or “pegs” connecting the internal stroma to the superficial stromatic crust or ascoma, 12–50×(7) 15–35 μm, brown to black, formed by cells 4–10 μm diam., with textura angularis. Mitotic multiplication: pycnidia (spermatogonia?) evident by stereomicroscopy as warts scattered among the acomata, corresponding to globose spaces underneath the stromatic crust, filled with numerous spores, which might be conidia or spermatia. Conidia (spermatia?) cylindrical, about 1.5×5 μm, hyaline, smooth. Ascomata. External appearance: superficial, occurring separately from, or more usually immersed in and merging with the stromatic crusts, mainly elongate, often confluent, about 0.5–2 mm long, dark-brown to black, initially irregular, becoming elliptical to boat-shaped, difficult to measure individually, opening by longitudinal slits. In vertical section: ascomata on the leaf cuticule, 100– 150 μm high, 180–550 (−650) μm wide, with an upper wall above the fertile locule. Upper wall: continuous with the stromatic crust, (16) 23–43 μm thick, dark, dense, composed of irregular, prismatic cells 10–12×3–7 μm, viewed in horizontal sections these cells form a radiating textura prismatica at the laciniate edge of the ascoma or the stromatic crust. Lower wall: a thin layer of hyphae in strands. Locule: 105–150×175–550 μm, composed of a thin basal cushion on the surface of the plant cuticule, with asci and interascal tissue above.
Mycol Progress (2012) 11:1–6
3
Fig. 1 Antoniomyces loranthicola (Parmulariaceae) on leaves of Gaiadendron punctatum. 1 Three colonies on a leaf in the field, together with epiphyllous lichens (Piepenbring 4994). 2 A fresh colony with a central part swollen due to the internal stroma, with ascomata, pycnidia, and radiating external hyphae, as seen with a stereomicroscope (Piepenbring 4994). The colony is wet so slits of the ascomata are open exposing the hymenia. Scale bar 2 mm. 3 Superficial view of part of a stromatic crust and radiating external hyphae, as seen with a stereomicroscope (Piepenbring 4994). Scale bar 1 mm. 4, 5 Colonies of a herbarium specimen as seen with a
stereomicroscope (UB 20339). Scale bars 1 mm. 4 Dry. 5 Wet. 6 Transverse section of an infected leaf with an adaxial colony, stroma located through the mesophyll, and stromatic development on the abaxial side of the leaf, as seen by light microscopy (UB 20339). Scale bar 100 μm. 7 Transverse section of part of a colony with adaxial tissue of the leaf, a stromatic crust connected to the internal stroma by a peg, and an ascoma with asci surrounded by pseudoparaphyses, as seen by light microscopy (UB 20339). Note brown tips of pseudoparaphyses and young ascospores stained with cotton blue. Scale bar 100 μm
Asci maturing sequentially. Young asci variable in shape before spores can be distinguished, sometimes slightly forked at the base, cylindric-clavate to clavate or broad-clavate, at first thin-walled, later thick-walled with a subapical chamber visible before spore delimitation. Mature asci (45–) 58–66 (−75)×(13–) 16–21 μm, cylindric-clavate to clavate, thick-walled particularly in the upper part, not changing colour in IKI, with mostly 8, rarely 6 spores arranged in one, two rows or sometimes in a cluster. Asci after spore release collapsed, with a large apical crack in the outer wall, and with the inner wall extending like a “tongue” through the crack; the extended inner wall sometimes with a tattered or broken apex.
Ascospores cylindric-ellipsoidal or ellipsoidal to narrowly ovoid, 1-septate, slightly narrowed at the septum, the lower cell slightly attenuated, the upper cell sometimes attenuated, (17–) 21–23 (−24)×7–9 (−11) μm, initially colourless with a mucilaginous sheath, becoming lightbrown to brown, verrucose, the mucilaginous sheath degenerating at maturity. Interascal tissue: formed by densely packed pseudoparaphyses which are filiform, 80– 90×1–1.5 μm, slightly swollen at tips (up to 1.5–5 μm diam.), mostly hyaline, sometimes with brown to dark brown external material adhering to the tips which are smooth to slightly verrucose, pseudoparaphyses septate, sometimes branched near the septa, branches arising in acute angles, surrounded by gelatinous material. By wetting
4
Mycol Progress (2012) 11:1–6
Fig. 2 Antoniomyces loranthicola (Parmulariaceae) on leaves of Gaiadendron punctatum as seen by light microscopy. 8 External hyphae with lateral ramifications anastomosing with adjacent hyphae (Piepenbring 4770b). Scale bar 50 μm. 9 Transverse section of the border of a stromatic crust (densely dotted) connected by a peg to internal stroma (Piepenbring 4770b). Note radiating, external hyphae
on the cuticule and dots in palisade cells indicating the presence of tannins. Scale bar 50 μm. 10 One young and three mature asci surrounded by pseudoparaphyses (Piepenbring 4770b). Scale bar 20 μm. 11 Two young ascospores with gelatinous sheaths and three mature ascospores (Piepenbring 4770b). Scale bar 5 μm
the ascoma, the gelatinous interascal tissue swells, the lobes of the stromatic crust are separated, and the hymenium is exposed, probably to liberate the ascospores under humid environmental conditions.
Specimens examined: On leaves of Gaiadendron punctatum (Ruiz & Pav.) G. Don (Loranthaceae). PANAMA. CHIRIQUI: Parque Internacional la Amistad, La Cascada trail, at the second lookout close to the highest point of the
Table 1 Morphological characteristics of the new genus of Antoniomyces and closely related genera in the Parmulariaceae Colony
External hyphae
Internal stroma
Antoniomyces
mostly circular to elliptical; plane
present; without appressoria
Aulacostroma
elongate, later circular, elliptical, or irregular; plane circular to elliptical; plane
present; with bulbil-like structures resembling appressoria absent
Hysterostomella
circular, elliptical, or irregular; plane
absent
Mintera
circular to elliptical; stellate by locules radiating from a central, wart-like stromatic projection; plane circular to elliptical; pulvinate
present; with lateral hyphopodiate appressoria
subepidermal; partially extensive; in some parts penetrating through the mesophyll; brown to black subcuticular; extensive; brown to black subcuticular; extensive; brown to dark brown; visible as dark ring around the colony subcuticular, intraepidermal, or in mesophyll cells; partially extensive; colourless to brown subcuticular; extensive; colourless to brown; with brown pegs
circular to elliptical; slightly stellate by radiating locules; plane
absent
Dothidasteroma
Symphaeophyma Viegasella
present; without appressoria
subcuticular; extensive; dark brown; visible as dark ring around the colony subcuticular; extensive; colourless; visible as pale greenish ring around the colony
Mycol Progress (2012) 11:1–6
trail, alt. approx. 2,340 ma.s.l., 8°54.1′N, 82°37.2′W, 4 March 2003, M. Piepenbring 3207, R. Kirschner et al. (M 0141259, PMA). At the same place, 22 September 2005, C. A. Inácio 825, M. Piepenbring et al. (UB col. micol. 20.338, 20339). At the same place, 23 April 2008, K. Araúz 2, M. Piepenbring, ANAM rangers et al. (M 0141260, PMA). At the same place, 18 May 2009, M. Piepenbring 4770b and maestria students (PMA). Attempts to obtain cultures from ascospores failed. This has also been the case for other species of Parmulariaceae (Inácio and Cannon 2008).
Discussion This species is the first report of a member of Parmulariaceae on a species of Loranthaceae and differs morphologically from all other known species of this family. For a comparison with morphologically closest genera, see Table 1. Aulacostroma Syd. & P. Syd. (Sydow and Sydow 1914) includes species with external hyphae with bulbil-like structures resembling appressoria but the internal stroma is always extensive and does not penetrate into the mesophyll as in the new species. Dothidasteroma Höhn. (Höhnel 1909, 1910) includes species with superficial ascomata connected to the host by stromatic pegs and has effuse internal stroma, but the internal stroma is not as deep as in the new species and the colonies lack external hyphae. The new species is also close to species of Hysterostomella Speg. (Spegazzini 1885), but in addition to having deeper internal stromata, it has external hyphae that clearly distinguishes it from species of that genus. The monotypic genus Viegasella Inácio & Cannon (Inácio and Cannon 2003) shows internal stromata somewhat similar to those of species of Aulacostroma and lack external hyphae and is thus distinct from the new species. The monotypic genus Mintera is distinct from the new species by having external hyphae with hyphopodia (appressoria sensu Mibey and Hawksworth 1995), ascomata with locules radiating from a central wart-like stromatic projection, and internal stroma similar to the stroma of species of Aulacostroma and Viegasella. Symphaeophyma Speg. (Spegazzini 1912) is another close genus but clearly differs by a rather extensive subcuticular internal stroma with few strands of hyphae spreading out from the margin of the ascomata. The family Parmulariaceae is probably closely related to Asterinaceae, with the delimitation of both families being based on the presence of external hyphae mostly with hyphopodia in species of Asterinaceae and the presence of an internal stroma in species of Parmulariaceae (Inácio 2003; Cannon and Kirk 2007; Kirk et al. 2008). Inácio and Cannon (2008) mentioned that they show a number of similarities which makes it difficult to separate them based only on morphological features and suggested complemen-
5
tary studies on evolutionary patterns of these families. In Asterinaceae, a genus close to genera in Parmulariaceae is Dothidasteromella Höhn. (Höhnel 1910) which shows superficial roundish ascomata, with irregularly arranged locules connected to a thin subcuticular internal stroma by narrow hyphae or stromatic columns, as well as a dense external hyphae without appressoria (Dennis 1970). This genus shows some similarities to the Parmulariaceae, where Aulacostroma, Dothidasteroma, Mintera, and Symphaeophyma have extensive flat subcuticular internal stromata, but Dothidasteroma does not have external hyphae and Aulacostroma and Mintera have external hyphae with structures which are presumed to be appressoria (Inácio and Cannon 2008). The new species shows a deep internal stroma that clearly differs from the stromata of known species. Another genus in Asterinaceae close to the new one is Viegasia Bat. (Batista 1951)which includes species with external hyphae which are easily distinguished from those of the new species by not forming distinctive appressoria. Another similar genus is Macowaniella Doidge that shows deep internal stroma, but Doidge (1921) mentioned that the asci are blue in iodine which is clearly distinct from the new species. Acknowledgements The authors thank Paul F. Cannon, Paul M. Kirk, Tina Hofmann, Uwe Braun, José Carmine Dianese, and David W. Minter for valuable comments for the improvement of the manuscript. The investigation was supported by the German Academic Exchange Service (DAAD), the Universidad Autónoma de Chiriquí (UNACHI), the FINATEC (Brazil) / UnB, FAPDF (Brazil), CNPq (Brazil), and the German Research Foundation (DFG). The Autoridad Nacional del Ambiente (ANAM, Panama) is thanked for collection and export permits. Carlos Antonio Inácio also acknowledges his students Gustavo Puga Lemes, and Thayara Oliveira Rodrigues for assistance, Mariza Sanchez (Mycological Herbarium).
References Batista AC (1951) Discussion on the genera Parmularia and Schneepia and election of new genus Viegasia. Bol Secr Agr Ind Com 18(1–2):29–34 Cannon PF, Kirk PM (2007) Fungal families of the world. CABI, Egham, UK Dennis RWG (1970) Fungus flora of Venezuela and adjacent countries. Kew Bulletin Additional Series III. Clowes, London Doidge EM (1921) South African Ascomycetes in the National Herbarium. Part I. Bothalia 1:5–32 Hibbett DS et al (2007) A high–level phylogenetic classification of the F u n g i . M y c o l R e s 111 ( 5 ) : 5 0 9 – 5 4 7 . d o i : 1 0 . 1 0 1 6 / j . mycores.2007.03.004 Höhnel FXR von (1909) Fragmente zur Mykologie (VIII. Mitteilung, Nr. 407 bis 467). Sitz Kais Akad Wiss Wien. Math nat Kl, Abt 1 118:1461–1552 Höhnel FXR von (1910) Fragmente zur Mykologie (X. Mitteilung, Nr. 468 bis 526). Sitz Kais Akad Wiss Wien. Math nat Kl, Abt 1, 119:393–473. Inácio CA (2003) A monograph of the Parmulariaceae. PhD thesis, University of London
6 Inácio CA (2005) Taxonomia da família Parmulariaceae. In: Luz WC (ed) Revisão Anual de Patologia de Plantas. Rev Anu Patol Plant 13:75–113 Inácio CA, Cannon PF (2003) Viegasella and Mintera, two new genera of Parmulariaceae (Ascomycota) with notes on the species referred to Schneepia. Mycol Res 107(1):82–92. doi:10.1017/S0953756202007013 Inácio CA, Cannon PF (2004) Rhagadolobium dicksoniifolium. IMI Descript Fungi Bact No. 1579 Inácio CA, Cannon PF (2008) The genera of the Parmulariaceae. CBS Biodiversity Series vol. 8. Utrecht, the Netherlands: CBS Fungal Biodiversity Centre Inácio CA, Minter DW (2002a) Aldona stella-nigra. IMI Descr Fungi Bact No. 1441 Inácio CA, Minter DW (2002b) Aldonata pterocarpi. IMI Descr Fungi Bact. Set 145 No. 1442 Inácio CA, Minter DW (2002c) Aulacostroma palawanense. IMI Descr Fungi Bact. Set 145 No. 1443 Inácio CA, Minter DW (2002d) Aulacostroma pandani. IMI Descr Fungi Bact. Set 145 No. 1444 Inácio CA, Minter DW (2002e) Cocconia concentrica IMI Descr Fungi Bact. Set 145 No. 1445 Inácio CA, Minter DW (2002f) Cycloschizon alyxiae. IMI Descr Fungi Bact. Set 145 No. 1446 Inácio CA, Minter DW (2002g) Cycloschizon brachylaenae. IMI Descr Fungi Bact. Set 145 No. 1447 Inácio CA, Minter DW (2002h) Cyclostomella disciformis. IMI Descr Fungi Bact. Set 145 No. 1448 Inácio CA, Minter DW (2002i) Englerodothis kilimandscharica. IMI Descr Fungi Bact. Set 145 No. 1449
Mycol Progress (2012) 11:1–6 Inácio CA, Pereira-Carvalho RC, Dianese JC (2011) A new Dothidasteroma species on leaves of Psidium laruotteanum from the Brazilian Cerrado. Mycotaxon 116:27–32. doi:10.5248/116.27 Kirk PM, Cannon PF, Minter DW, Stalpers JA(2008) Dictionary of the fungi, 10th edn.CABI, Wallingford Lumbsch HT, SM Huhndorf (ed) (2007) Outline of Ascomycota – 2007. Myconet 13:1–58 Lumbsch HT, SM Huhndorf (ed) (2010) Myconet Volume 14 (Part One. Outline of Ascomycota – 2009). Part Two. Notes on Ascomycete Systematics. Nos. 4751–5113. Fieldiana Life Earth Sci 1:1–64 Mibey RK, Hawksworth DL (1995) Diporothecaceae, a new family of ascomycetes, and the term “hyphopodium”. Syst Ascomycetum 14(1):25–31 Rizzini CT (1960) Loranthaceae. In: Woodson RE & Schery RW (eds) Flora of Panama, Annls Miss Bot Gard 47:263–359. Sivanesan A (1970) Parmulariopsella burseracearum gen. et sp. nov. and Microcyclus placodisci sp. nov. Trans Br Mycol Soc 55 (3):50–514 Sivanesan A, Sinha ARP (1989) Aldonata, a new ascomycete genus in the Parmulariaceae. Mycol Res 92(2):246–249 Sivanesan A, Hsieh WH, Chen CV (1998) A new monotypic genus of a parmulariaceous dictyosporous ascomycete from Taiwan. Bot J Linn Soc 126:323–326 Spegazzini CL (1885) Fungi Guaranitici. Pugillus 1. An Soc Cient Arg 19 (6):241-265 [nos 268–315] Spegazzini CL (1912) Mycetes Argentinenses. Series VI. An Mus Nac Hist Nat B Aires 23:1–146 [nos 1212–1546] Sydow H, Sydow P (1914) Fungi from northern Palawan. Philipp J Sc Sect C, Bot 9(2):157–189
