Abstract
An unusual fungus with a novel set of morphological, ecological, and DNA sequence characteristics was found to be causing necrosis of distal portions of living leaves and sterility of Parodiophyllochloa cordovensis (Poaceae) in Panama. The small, superficial, soft-textured yellow perithecia develop directly on the surface of the necrotic plant tissue. The unitunicate asci are filled with hyaline, long-fusiform, typically 6–12-septate ascospores that disarticulate into secondary part-ascospores that later produce tertiary spores. This undescribed fungus could not be cultured, nor was an asexual state observed. Morphological characteristics are inconsistent with any existing generic concept, but suggest a close phylogenetic relationship with species of Hypocreales. This was confirmed by molecular phylogenetic analysis of nrLSU rDNA sequences. While host relationship and disarticulation of ascospores suggest an affinity between this fungus and species of Clavicipitaceae, its colonization of necrotic tissue of a living host, lack of stromata, non-thickened apices of the asci, and long-fusiform (not filiform) ascospores suggest otherwise. Furthermore, this fungus differs morphologically from species in Bionectriaceae and Nectriaceae in its disarticulating long-fusiform ascospores, part-ascospores producing tertiary spores, and occurrence on living grasses. Our phylogenetic analysis of combined ITS, nrLSU, and TEF1 sequences yielded evidence for placement of the new species within the Hypocreales, close to Bionectriaceae and Nectriaceae. However, our analysis did not specifically clarify and support the species’ membership within either family. This fungus is described as Microchrysosphaera graminicola, a new genus and species belonging to the Hypocreales, incertae sedis.
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References
Bischoff JF, White JF (2003) The plant-infecting clavicipitaleans. In: White JF Jr, Bacon CW, Hywel-Jones NL, Spatafora JW (eds) Clavicipitalean fungi, evolutionary biology, chemistry, biocontrol, and cultural aspects. Mycology series 19. Marcel Dekker, New York, pp 125–149
Carbone I, Kohn LM (1999) A method for designing primer sets for speciation studies in filamentous ascomycetes. Mycologia 91:553–556
Castlebury LA, Rossman AY, Sung GH, Hyten AS, Spatafora JW (2004) Multigene phylogeny reveals new lineage for Stachybotrys chartarum, the indoor air fungus. Mycol Res 108:864–872. doi:10.1017/S0953756204000607
Hirooka Y, Rossman AY, Samuels GJ, Lechat C, Chaverri P (2010) A monograph of Allantonectria, Nectria, and Pleonectria (Nectriaceae, Hypocreales, Ascomycota) and their pycnidial, sporodochial, and synnematous anamorphs. Stud Mycol 71:1–210
Huelsenbeck JP, Ronquist F (2001) MrBayes: Bayesian inference of phylogenetic trees. Bioinformatics 17:754–755
Katoh K, Toh H (2008) Recent developments in the MAFFT multiple sequence alignment program. Brief Bioinform 9:286–298. doi:10.1093/bib/bbn013
Katoh K, Misawa K, Kuma K, Miyata T (2002) MAFFT: a novel method for rapid multiple sequence alignment based on fast Fourier transform. Nucleic Acids Res 30:3059–3066. doi:10.1093/nar/gkf436
Kearse M, Moir R, Wilson A, Stones-Havas S, Cheung M, Sturrock S, Buxton S, Cooper A, Markowitz S, Duran C, Thierer T, Ashton B, Meintjes P, Drummond A (2012) Geneious Basic: an integrated and extendable desktop software platform for the organization and analysis of sequence data. Bioinformatics 28:1647–1649. doi:10.1093/bioinformatics/bts199
Kirk PM, Cannon PF, David JC, Stalper JA (2008) Ainsworth & Bisby’s Dictionary of the Fungi, 10th edn. CABI Bioscience, Wallingford
Lücking R (2007) The fungi Microstelium hyalinum and Acrospermum puiggarii are the same as the lichen Gomphillus ophiosporus (Ostropales: Gomphillaceae). Bryologist 110:475–479
Morrone O, Denham SS, Aliscioni SS, Zuloaga FO (2008) Parodiophyllochloa, a new genus segregated from Panicum (Paniceae, Poaceae) based on morphological and molecular data. Syst Bot 33:66–76
Nylander JAA, Wilgenbusch JC, Warren DL, Swofford DL (2007) AWTY (are we there yet?): a system for graphical exploration of MCMC convergence in Bayesian phylogenetics. Bioinformatics 24:581–583
Posada D (2008) jModelTest: phylogenetic model averaging. Mol Biol Evol 25:1253–1256. doi:10.1093/molbev/msn083
Posada D, Buckley T (2004) Model selection and model averaging in phylogenetics: advantages of Akaike information criterion and Bayesian approaches over likelihood ratio tests. Syst Biol 53:793–808. doi:10.1080/10635150490522304
Reddy PV, Bergen MS, Patel R, White JF Jr (1998) An examination of molecular phylogeny and morphology of the grass endophyte Balansia claviceps and similar species. Mycologia 90:108–117
Rehner SA, Buckley E (2005) A Beauveria phylogeny inferred from nuclear ITS and EF1-alpha sequences: evidence for cryptic diversification and links to Cordyceps teleomorphs. Mycologia 97:84–98
Rossman AY, Samuels GJ, Rogerson CT, Lowen R (1999) Genera of Bionectriaceae, Hypocreaceae and Nectriaceae (Hypocreales, Ascomycetes). Stud Mycol 42:1–248
Samuels GJ, Rossman AY, Chaverri P, Overton BE, Põldmaa K (2006) Hypocreales of the Southeastern United States: an identification guide. CBS Biodiversity Series No. 4. Centraalbureau voor Schimmelcultures, Utrecht
Sung GH, Hywel-Jones NL, Sung JM, Luangsa-ard JJ, Shrestha B, Spatafora JW (2007) Phylogenetic classification of Cordyceps and the clavicipitaceous fungi. Stud Mycol 57:5–59. doi:10.3114/sim.2007.57.01
Talavera G, Castresana J (2007) Improvement of phylogenies after removing divergent and ambiguously aligned blocks from protein sequence alignments. Syst Biol 56:564–577. doi:10.1080/10635150701472164
Vilgalys R, Hester M (1990) Rapid genetic identification and mapping of enzymatically amplified ribosomal DNA from several Cryptococcus species. J Bacteriol 172:4238–4246
White JF Jr, Glenn AE (1994) A study of two fungal epibionts of grasses: structural features, host relationships, and classification in the genus Myriogenospora (Clavicipitales). Am J Bot 81:216–223
White TJ, Bruns TD, Lee S, Taylor J (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ (eds) PCR protocols: a guide to methods and applications. Academic, San Diego, pp 315–322
White JF Jr, Reddy PV, Glenn AE, Bacon CW (1997) An examination of structural features and relationships in Balansia subgenus Dothichloë. Mycologia 89:408–419
Acknowledgments
The authors thank V. Araúz, G. Avendaño, A. Hertz, T. Hofmann, A. Kreutle, J.M. Pérez, M. Rosas, S. Rudolph, G. Steinbeisser, and especially R. Mangelsdorff for help during field work; A. Ismaiel for assistance in the laboratory; and C. Herrera and R. Kepler for fruitful discussion on an early state of the manuscript. Observations, identification and the photo of flies in contact with the fungus were contributed by R. Mangelsdorff. We also thank J.F. Bischoff and J.F. White for collaboration at the beginning of the investigation. We gratefully acknowledge the German Academic Exchange Service (DAAD), the Deutsche Forschungsgemeinschaft (DFG), and the USDA Forest Service International Program for financial support and the Universidad Autónoma de Chiriquí (UNACHI) for logistical collaboration. We also thank the Autoridad Nacional del Ambiente (ANAM) for collecting and export permits. This study was supported by the LOEWE excellence initiative of the state of Hesse within the framework of the Cluster for Integrative Fungal Research (IPF).
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Judith, C., Rossman, A.Y., Kennedy, A.H. et al. Microchrysosphaera graminicola, an enigmatic new genus and species in the Hypocreales from Panama. Mycol Progress 14, 72 (2015). https://doi.org/10.1007/s11557-015-1095-2
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DOI: https://doi.org/10.1007/s11557-015-1095-2