ISSN (print) 0093-4666 © 2010. Mycotaxon, Ltd. ISSN (online) 2154-8889 MYCOTAXON Volume 113, pp. 397–404 doi: 10.5248/113.397 July–September 2010 Chaetospermum setosum sp. nov. from the Western Ghats, India Kunhiraman C. Rajeshkumar, Paras N. Singh, Lal S. Yadav, Santosh V. Swami & Sanjay K. Singh* rajeshfungi@gmail.com & singhsksingh@rediffmail.com* National Facility for Culture Collection of Fungi MACS’Agharkar Research Institute, G.G. Agarkar Road Pune—411004 India Abstract – A new species of Chaetospermum, Ch. setosum, is described based on the presence of conidiomatal setae and differences in conidial size and shape. This species occurs on Mangifera indica (Anacardiaceae) collected from Bhima Shankar forests in the Western Ghats of Maharashtra, India. The presence of conidiomatal setae is a unique character that differentiates this species from related taxa. Key words – anamorphic fungi, Efibulobasidium, Sebacinales Introduction During July 2009 a survey was conducted to explore the microfungal diversity in the natural forests of Bhima Shankar situated in the northern part of the Western Ghats, India, at 19°40’00”–19°42’09”N 73°29’16”–73°38’06”E with an altitude of 945 msl. The forest types are mainly evergreen and semi-evergreen with rainfall up to 6000 mm per annum (Janardhanan 1966). An unusual Chaetospermum species was found on fallen leaves of Mangifera indica. The presence of gelatinous conidiomata, holoblastic sympodial conidiogenesis, and cylindrical, non-septate conidia with tubular appendages are the distinguishing features of the genus Chaetospermum (Sutton 1980; Nag Raj 1993). Species of Chaetospermum are recorded worldwide as common saprophytes isolated from freshwater and litter. Sequences of two species of Chaetospermum suggest that members of this genus are basidiomycetes in the order Sebacinales (Rungjindamai et al. 2008). The anamorph-teleomorph relationship between * Corresponding author 398 ... Rajeshkumar & al. Chaetospermum and a known species of Sebacinales, Efibulobasidium albescens (Sacc. & Malbr.) K. Wells, was suggested by Wells & Bandoni (2001) and confirmed recently by Kirschner & Oberwinkler (2009). Chaetospermum setosum, which differs from the other five species described in that genus based on the presence of conidiomatal setae, cylindrical or V- and Y-shaped conidia, and number of polar appendages, is described as new to science. Materials and methods Conidiomata of the fungus were isolated from the lower surface of fallen leaves and observed under a Nikon Binocular stereo microscope (Model SMZ – 1500 with Digi-CAM, Japan). The serial dilution method was used to isolate this fungus (Pramer & Schmidt 1965) and the hyphal elements from the growing margin of the pure colonies developing from single spores were transferred to new Potato Dextrose Agar plates (PDA). For morphotaxonomic studies and photomicrographs an Olympus CX-41 (Japan) microscope was used. Conidia, setae, and conidiophores were measured using an ocular micrometer. The growth patterns of the colonies were also studied on different culture media viz. Czapek Yeast Autolysate Agar (CYA), Malt Extract Agar (MEA), Potato Carrot Agar (PCA), and PDA (Himedia Mumbai, India). Development was also observed on modified 2% agar media (2 g crushed autoclaved mango leaves mixed in 2% agar). The specimens were deposited in Ajrekar Mycological Herbarium (AMH) and the culture was accessioned and preserved in National Fungal Culture Collection of India (WDCM-932), Agharkar Research Institute, Pune, India. Taxonomic description Chaetospermum setosum Rajeshkumar, S.K. Singh & P.N. Singh, sp. nov. MycoBank MB 515508 Plates 1, 2 Foliicola. Conidiomata pycnidioidea, 300–750 µm diam., subepidermalia, primum immersa, postremo erumpentia, gelatinosa, nivea ad cremea ubi humida, palllide brunnea ad atrobrunnea ubi sicca. Setae marginales 120–132 µm longae, 5 µm latae ad basim, pallidae ad atrobrunneae, gradatim contractae versus apicem, acuminatae, crassitunicatae, solitariae vel binatim, 1–2-septatae ad basim. Conidiophora ramosa, hyalina, laevia. Cellulae conidiogenae cylindracae, holoblasticae, sympodiales, conidia maximam partem terminalia interdum lateralia, 1–4 in fasciculis. Conidia unicellularia, cylindracea vel variabilia in forma, recta vel curva, hyalina, laevia, guttulata, apice obtusa, 17–29(–40) × 4.4–7 µm. Appendices polares, nonramosae, tubulares, 2–5, praeciupue 3–4, 7.5–12.5 µm longae. Plate 1. Chaetospermum setosum (holotype). a. Habit. b–c. Conidiomatal setae. d. Conidiomatal setae and conidia. e. Conidiophores branching and conidiogenous cells. f. Conidial development g. Mature conidia with appendages. h–k. Branched and irregularly shaped conidia with appendages. Bars: d = 50 µm; e–k = 10 µm. Chaetospermum setosum sp. nov. (India) ... 399 400 ... Rajeshkumar & al. Etymology: from Latin setosus referring to the conidiomatal setae present in this species. Holotype: India, Bhima Shankar, Western Ghats, Maharashtra, on fallen leaves of Mangifera indica L. (Anacardiaceae) 30 Nov 2009, K.C. Rajeshkumar, AMH 9299. (Ex-type culture NFCCI 1912.) Foliicolous. Conidiomata pycnidial, 300–750 µm diam., initially immersed, subepidermal, ultimately erumpent, opening by an irregular split in apical wall, gelatinous, pearl white to creamish when moist, pale brown to dark brown when dry, scattered to gregarious, confluent. Setae marginal, 120–132 µm long, 5 µm wide at the base, pale to dark brown, gradually tapering towards the pointed apex, wall thickened, solitary or in pairs, one to two septate at base. Conidiophores arising from innermost wall of conidiomata, branched, hyaline, smooth. Conidiogenous cells cylindrical, holoblastic, sympodial, conidia mostly terminal, sometimes lateral, 1–4 in clusters. Conidia unicellular, cylindrical or variable in shape, sometimes branched, each branch bearing appendages, straight or curved, hyaline, guttulate, smooth-walled, apex obtuse, 17–29 (–40) × 4.5–7 µm (mean 24.2 × 5.3 µm), length-width ratio 4.6:1; appendages polar, unbranched, tubular, 2–5 at each end, usually 3–4, 7.5–12.5 µm long. Teleomorph: Unknown; no sexual state or fungus resembling Efibulobasidium was present near the specimen. Colonies on PDA slowly growing, 15 mm diam. after 7 days and 25 mm diam after 15 days, white, dull white to pale creamish white, with slight ridges and furrows, smooth, flat, margin irregular, aerial mycelium scanty, reverse creamish or dull white. Colonies on MEA slowly growing, 10 mm diam. after 7 days, white, velutinous, smooth, margin irregular, reverse white to off-white. Colonies on PCA fast growing, 60 mm diam. after 7 days, white or off-white, mycelium immersed forming a film over media, flat, margin regular, colonies rounded, reverse white to off-white. Colonies on CYA fast growing, 65 mm diam. after 7 days, creamish white, mycelium immersed forming thin flat colonies, margin regular, reverse white to off-white. Sporulation and conidium morphology on these media were similar to those in nature, but setae were not found. Sterile seta-like structures developed from the conidiomata in culture grown on modified 2% agar media with crushed autoclaved mango leaves. The sterile hyphae were hyaline or hyaline with dark brown pigmented areas scattered on it, thin-walled, wavy, with a broader base and blunt tip arising from the margins of the gelatinous conidiomata. Sporulation on this medium was poor. Discussion Saccardo (1892) established the genus Chaetospermum Sacc. based on Tubercularia chaetospora Pat. (Patouillard 1888), now Ch. chaetosporum (Pat.) Chaetospermum setosum sp. nov. (India) ... 401 Plate 2. Chaetospermum setosum (holotype). a. Conidiomatal setae. b. Mature conidia with appendages. c. Conidiophores branching and conidiogenous cells. d. Conidiophores and terminal clusters of conidia. Bars: a = 50 µm; b–d = 10 µm. A.L. Sm. & Ramsb. (Smith & Ramsbottom 1914). Saccardo (1892) published a superfluous new name for the type, Ch. tubercularioides Sacc., nom. nov., nom. illegit.; this is clearly a homotypic synonym, and not heterotypic as Nag Raj (1993) mistakenly indicated. Nag Raj (1993), who provided the most recent account of the genus Chaetospermum, accepted four species: Ch. chaetosporum, Ch. artocarpi (Nag Raj) Nag Raj, Ch. camelliae Agnihothr., and Ch. gossypinum 402 ... Rajeshkumar & al. (G.F. Atk.) Nag Raj. He separated these species based on conidial length-width ratio, conidial width, and the position of appendages. He also clarified that conidial appendages in all the taxa in this genus are tubular. Previously, Sutton (1980) had accepted three species of Chaetospermum viz., Ch. carneum Tassi, Ch. chaetosporum and Ch. gelatinosum Petch (1917); however, Nag Raj (1993) placed Ch. gelatinosum in synonymy with Mastigonema gelatinosum (Berk. & Broome) Nag Raj and, following an examination of the type specimen, considered Ch. carneum a nomen dubium. Talde (1981) described Chaetospermum indicum Talde from India. The type specimen is missing in AMH and not available for re-examination. The description and illustration of Ch. indicum suggest that this species is identical with the type species, Ch. chaetosporum. Thus, Ch. indicum is treated here as a synonym of Ch. chaetosporum. In the present study Chaetospermum setosum is proposed as a new species based on its unique morphological characteristics including the presence of conidiomatal setae, variously shaped conidia, and number and origin of the conidial appendages. The presence of conidiomatal setae has not been previously described in Chaetospermum. The conidial appendages are polar in Ch. artocarpi (as in Ch. setosum) but are circumpolar to sub-polar or lateral in the other two species. Although the presence of polar appendages in Ch. setosum suggests an affinity with Ch. artocarpi, they are more variable, with as many as 5 appendages sometimes present. Infundibura adhaerens Nag Raj & W.B. Kendr. (anamorph of Helicogloea angustispora L.S. Olive) is another basidiomycetous anamorph that produces sterile seta-like structures in nature as well as culture. Different authors (Nag Raj & Kendrick 1981; Matsushima 1996; Wu et al. 1997) have given different descriptions for sterile hyphae (setae) in this species. Kirschner (2004), who describes them as hyaline, aseptate, and thick-walled, notes that these differences may be due to intraspecific variation, environmental influences, or aging. Chaetospermum setosum also produces setae in nature and sterile hyphae (setae) in culture. In nature the setae are dark brown, erect, with pointed tips, but in culture hyaline or hyaline with dark brown pigmented areas, thin-walled, wavy, and bluntly tipped. This observation indicates that setal characteristics depend on environmental factors and culture conditions. Key to species of Chaetospermum 1. 1. 2. 2. Conidiomata with marginal setae; conidia cylindrical to V- or Y-shaped, appendages polar, 2–5 at each end. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ch. setosum Conidiomata without setae; conidia ellipsoidal to cylindrical . . . . . . . . . . . . . . . . .2 Appendages polar, 3, rarely 2, appendages on each conidium; conidia 18–26 × 4.5–5.5 µm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ch. artocarpi Appendages circumpolar to subpolar or lateral . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Chaetospermum setosum sp. nov. (India) ... 403 3. 3. Appendages circumpolar to subpolar; conidia 26–41 × 8–12 µm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ch. chaetosporum Appendages subpolar or lateral; conidia less than 8 µm wide . . . . . . . . . . . . . . . . .4 4. 4. Appendages 9–20 µm long; conidial length-width ratio 5.5:1 . . . . . . Ch. camelliae Appendages 18–20 µm long; conidial length-width ratio 6.3:1 . . . Ch. gossypinum Acknowledgements We are indebted to Dr. Amy Y. Rossman, Systematic Mycology & Microbiology Lab., USDA, ARS, Beltsville, U.S.A., and Dr. Roland Kirschner, Department of Mycology, Institute of Ecology, Evolution & Diversity, J.W. Goethe-University, Frankfurt am Main, Germany, for reviewing this manuscript. Thanks are also to Department of Science and Technology (DST) Govt. of India, New Delhi for providing financial support under IRHPA programme for setting up state-of the-art National Facility for Culture Collection of Fungi (No. SP/SO/PS-55/2005) at Agharkar Research Institute, Pune, India. Literature cited Agnihothrudu V. 1962. Notes on fungi from North East India X. Chaetospermum camelliae sp. nov. on tea (Camelliae sinensis (L.) O. Kuntze). Mycopathologia et Mycologia Applicata 16: 113–116. doi:10.1007/BF02089127 Janardhanan KP. 1966. The Flora of Bhima Shankar and surrounding areas of the Khed Taluka, Pune District (Maharashtra State), Ph.D. thesis, 3 vol. Unpublished. Kirschner R. 2004. Sporodochial anamorphs of species of Helicogloea. In: Agerer R, Piepenbring M, Blanz P. (eds): Frontiers in basidiomycote mycology, IHW Verlag. 165–178. Kirschner R, Oberwinkler F. 2009. Supplementary notes on Basidiopycnis hyalina (Basidiomycota, Atractiellales) and its anamorph. Mycotaxon 109: 29–38. Matsushima T. 1996. Matsushima mycological memoirs No. 9. Kobe (published by the author). Nag Raj TR. 1993. Coelomycetous anamorphs with appendage-bearing conidia. Mycologue Publications, Waterloo, Ontario, Canada. 1101 pp. Nag Raj TR, Kendrick B. 1981. Infundibura, a new hyphomycete with unique appendages. Canadian Journal of Botany 59: 542–546. Patouillard MN. 1888. Note sur une Tubercularée graminicole. Bulletin de la Société Mycologique de France 4: 39–40. Petch T. 1917. Additions to Ceylon fungi. Annual Review of Botanical Gardens, Peradenia 6(3): 195–256. Pramer D, Schmidt EL. 1966. Experimental soil microbiology. Burges Publishing Co., Minnepolis, Minnesota. 106 pp. Rungjindamai N, Skayaroj J, Plaingam N, Somrithipol S, Jones EBG. 2008. Putative basidiomycete teleomorphs and phylogenetic placement of the coelomycete genera: Chaetospermum, Giulia and Mycotribulus based on nu-rDNA sequences. Mycological Research 112: 802–810. doi:10.1016/j.mycres.2008.01.002 Saccardo PA. 1892. Supplementum universale, Pars II. Discomyceteae-Hyphomyceteae. Sylloge Fungorum 10: 1–964. Smith AL, Ramsbottom J. 1914. New or rare fungi. Transactions of the British Mycological Society 4: 318–330. doi:10.1016/S0007-1536(12)80035-0 404 ... Rajeshkumar & al. Sutton BC. 1980. The coelomycetes: Fungi imperfecti with pycnidia, acervuli, and stroma. Commonwealth Mycological Institute, Kew, Surrey, England. 696 pp. Talde UK. 1981. Aquatic deuteromycetous fungi from Purna and Dudhna Rivers. Indian Journal of Mycology and Plant Pathology 11: 288–290. Wells K, Bandoni RJ. 2001. Heterobasidiomycetes. In: McLaughlin, DJ, EG McLaughlin, and PA Lemke (eds.): The Mycota VII Part B: 85–120. Wu W, Sutton BC, Gange AC. 1997. Notes on three fungicolous fungi: Anastomyces microsporus gen. et sp. nov., Idriella rhododendri sp. nov. and Infundibura adhaerens. Mycological Research 101: 1318–1322. doi:10.1017/S0953756297004097