Abstract
As part of a long term study of fungi colonizing submerged wood in freshwater streams a new Annulatascus species, A. aquatorba, is described and illustrated from Erythrophleum teysmannii test blocks from Sirindhorn Peat Swamp Forest, southern Thailand. It differs from other species in the genus in ascospore measurements, thickness of the cell wall, 1–3-septate, fusoid to lunate shape, with central brown cells and subhyaline end cells and without a mucilaginous sheath. Asci are cylindrical, pedicellate, with a distinct, wedge-shaped and non-amyloid apical ring. Phylogenetic relationships of this species, based on the combined partial 18S and 28S rDNA, place it in the same clade as A. velatisporus (type species), A. hongkongensis and A. nilensis.
Acknowledgments
This study was supported by the TRF/BIOTEC special Program for Biodiversity Research and Training grants BRT R_145006, BRT R_252057 and R_251009.
Prof Morakot Tanticheroen, Drs Kanyawim Kirtikara and Lily Eurwilaichitr at BIOTEC are thanked for their continued support of the freshwater work in Thailand. Our thanks to Sunthorn Taodam for support with the field work at Sirindhorn Peat Swamp, Jureerat Ueapattanakit for DNA extraction and PCR of Annulatascus aquatorba, Juntima Chanprasert for running the RAxML analysis, Prof Mohamed A. Abdel-Wahab for the sequence of A. nilensis and Dr Clement K.M. Tsui for invaluable comments on Annulatascus taxonomy. We are also grateful for the help of two anonymous reviewers who provided critical comments that improved the manuscript.