Aenigmatospora, an enigmatic new genus of fungi from tropical leaf litter

Aenigmatospora, an enigmatic new genus of fungi from tropical leaf litter

Cryptogamie, Mycol., 1999, 20 (2): 113-117 Aenigmatosporu, an enigmatic 113 new genus of fungi from tropical leaf litter R.E CASTANEDA”, M. SAIKA...

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Cryptogamie, Mycol., 1999, 20 (2): 113-117

Aenigmatosporu, an enigmatic

113

new genus of fungi from tropical

leaf litter

R.E CASTANEDA”, M. SAIKAWAb, C. DECOCK=*, J. GUARRod & M. CALDUCHd a Institute de Investigaciones Fundamentales en Agricultura Tropical ‘Alejandro de Humbolt” callel, esq.2, Santiago de Las Vegas, Ciudad de La Habana, Cuba. C.P. 17200. b Department of Biology, Tokyo Gakugei University, Nukuikita-machi, Koganei-shi, Tokyo 184, Japan. ’ Mycotheque de l’universite catholique de Louvain (MUCL), Fact& des sciencesagronomiques,place Croix-du-Sud 3, B-1348 Louvain-La-Neuve, Belgium. d Unitat de Microbiologia, Facultat de Medicina i Ciencies de la Salut, Universitat Rovira I virgili, 43201 Reus, Spain. (Received 20 January 1999, accepted 25 February 1999)

Abstract - Aenigmatospora pulchra gen. et sp. nov. found on fallen decaying leaves of Ficus elastica Roxb.: Homem (Moraceae) in a rainforest in Cuba is described and illustrated. This fungus is characterized by sporophores which are cylindrical, colourless, branched at the apex, and above all, by spores which are mushroom-shaped, colourless, and borne singly and asymmetrically at the apex of the sporogenous cells, to which they often remain attached at maturity. The taxonomic position of this fungus is uncertain.0 ADAC I Elsevier, Paris fungi I Aenigmatospora pukhra I taxonomy

I Cuba

R&urn6 - Aenigmatospora pulchra gen. nov. et sp. nov., est d&it et illustre. Le champignon a et6 observe sur feuilles pourrissantes de Ficus elastica Roxb. : Homem (Moraceae), gisant au sol dans la for& tropicale cubaine. Le genre s’individualise par des hyphes sporogenes cylindriques, incolores, ramifiees a leur sommet, et surtout par la formation de spores hyalines ayant la forme d’un chapeau classique de basidiomycete, naissant de faGon asymetrique et solitaire au sommet des cellules sporogenes ; a maturite, les spores restent souvent attachees aux cellules sporogenes. La position taxonomique de cette mucedinee est incertaine. 0 ADAC I Elsevier, Paris champignon

I Aenigmatospora pulchra I taxonomie I Cuba

During a survey of leaf litter inhabiting microfungi in a tropical rainforest in Cuba, an unusual fungus was collected on a decaying leaf of Ficus elastica Roxb.: Homem (Moraceae) in litter. This fungus is characterized by few septate sporophores, * Correspondence and reprints.

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R.F. Casttieda,

M. Saikawa, C. Decock, J. Guarro 8z M. Calduch

bearing at their apex a radiating cluster of sporogenoushyphae, each of them supporting at its apex a single mushroom-shapedspore, which is borne asymmetrically and often remains firmly attached at maturity. The sporogenoushyphae are smooth below and become progressively echinulate above, as is the basalpart of the spore.All attempts to obtain an axenic culture from sporesor mycelium failed. While this organism undoubtedly belongs to fungi sensulate (Barr, 1992), its taxonomic placement remains uncertain and it could not be assignedto any existing fungal genus, order or even class.A new taxon is proposed, in the hope that additional collections will provide more information and will allow this fungus to be placed more precisely in an appropriate taxonomic niche.

Fig. 1. Sporophores,

sporogenous cells and spores. Scale bar = 10 pm.

Aenigmatosporu, an enigmatic new genus of fungi from tropical leaf litter

115

DESCRIPTION

Aenigmutosporu R.F. Castafieda Ruiz, Saikawa, Guarro et Calduch gen. WV. Coloniue e$usae, albae. Mycelium partim superficiale et partim in substratum immersum. Sporophora conspicua, erecta vel prostrata, recta vel flexuosa, cylindrica, septata, ramosa ad apicem, hyalina. Cellulae sporogenae monoblasticae, cylindricae vel ampulliformes, discretae, determinatae, interdum reliquiae sporae ad apicem retinentes, in fasciculo ad apicem oriundae. Sporae agariciformes, unicellulares, hyalinae, laeves vel echinulatae, siccae vel leniter hygroscopicae, plerumque in man&ate persistentes in loco sporogeno. Species typica: Aenigmatospora pulchra sp. nov. Colonies effuse, white. Mycelium superficial and immersed. Sporophores differentiated, erect or prostrate, straight or flexuous, cylindrical, septate, branched at the apex, hyaline. Sporogenous cells monoblastic, cylindrical or ampulliform, discrete, determinate, arranged in a fascicle at the apex of the sporophores. Spores mushroom-shaped, one-celled, colourless, echinulate or smooth, dry or slightly hygroscopic, usually remaining attached to the sporogenous cells. Type species: Aenigmatospora pulchra sp. nav. Etymology: L. Aenigmato, meaning enigmatic, -spora, meaning spore.

Aenigmatospora pulchra R.F. Castaiieda Ruiz, Saikawa, C. Decock, Guarro et Calduch sp. nov. Coloniae in substrato naturali e$usae, pilosae, amphigenae, albae. Mycelium partim superjiciale et partim in substratum immersum. Hyphae septatae, ramosae, laeves, hyalinae. Sporophora conspicua, mononemata, erect, recta vel flexuosa, raro prostrata, 170-370 pm alta, IO-15 pm crassa ad basim, cylindrica, 2-3-septata, ramosa ad apicem, levia, hyalina. Cellulae sporogenae 6-12, discretae, laeves ad basim et echinulatae ad apicem, 15-23 x 6-7 pm, 4-5 pm late in parte intermediae, hyalinae, interdum reliquiae sporae ad apicem retinentes, fasciculatae ad apicem dispositae. Sporae agariciformes, ellipsoideae vel lageniformes ad basim, hemisphaericae vel concavae ad apicem 15-20 pm longae, 5-7 pm crassae infra; 14-l 7 pm diam. supra, unicellulares, solitariae, siccae vel leniter hygroscopicae, echinulatae infra et leves supra; hyalinae, ex sublaterales et excentricae oriundae; plerumque in maturitate persistentes in loco sporogeno. Holotypus: MUCL 40711, in foliis dejectis Ficis elasticae Roxb.: Homem, in sylva tropicalis, Santiago de Las Vegas, Cuba. Leg. R.F. Castaiieda Ruiz 8-X-1997. Colonies on the natural substrate effuse, hairy, amphigenous, white. Mycelium superficial and immersed. Hyphae septate, branched, smooth-walled, hyaline, 2-5 pm diameter. Sporophores differentiated, mononematous, erect, straight or flexuous, rarely prostrate, 17&370 pm long, 10-15 pm wide at the base, cylindrical, 2-3-septate, branched at the apex, smooth, hyaline. Sporogenous cells discrete, 6-12, radiating from the apex of the sporophores, smooth at the sometimes slightly swollen base and echinulate towards the apex, 15-23 x 6-7 pm, 4-5 pm wide at the center, hyaline. Spores mushroom-shaped, ellipsoid or lageniform at the base, semispherical, lenticular to concave at the apex, 15-20 pm long, 5-7 pm wide below, 14-17 pm diameter at the apex, one-celled, solitary, dry or slightly hygroscopic, echinulate at the base and smooth-walled at the apex, hyaline, usually remaining attached to the sporogenous cells at maturity, eccentric and sublaterally arranged at the top of sporogenous cells. Substrate: On fallen decaying leaves of Ficus elastica Roxb.: Homem, in a tropical forest, Santiago de Las Vegas, Cuba. Coll. R.F. Castaheda Ruiz, 8-X-1997, holotype, MUCL 407 11.

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R.F. Castaiieda, M. Saikawa, C. Decock, J. Guarro & M. Calduch

Plati e 1. a) Sporophore, sporogenous cells and spores, bd) e-f) Spores. Scale bar = 10 pm.

Sporogenous cells and attached spot-es,

Aenigmatospora,

an enigmaticnew genusof fungi from tropical leaf litter

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The ontogenesis,liberation and dispersalmechanismsof the sporesof A. pulchru are enigmatic. They often remain attached to the sporogenouscells at maturity. However, some of the sporogenouscells shows a remnant of the spore similar to a rhexolytic conidial secession,although, no frill or scar is observed on the surface of the spores. The genus Searchomyces B.S. Mehrotra & M.D. Mehrotra (Chandrashekara 1978) superficially resemblesAenigmatosporu. However, the former has well-developed conidiogenous cells with several ramoconidia or separating cells which bear obovoid, ellipsoid to obclavate, one-celled, colourlessconidia, and conidium secessionis clearly schizolytic. Acknowledgements. R.F. Castaiieda Ruiz gratefully acknowledges the CubanMinistry of Agriculture for facilities provided.

REFERENCES

BARR D.J.S., 1992- Evolution andkingdomsof organisms from the perspective of a mycologist. Mycologia

84: 1-11.

CHANDRASHEKARA K.V., 1978- The genusSearchomyces. Kavaka 6: 49-54.