Borealophlyctis nickersoniae, a new species in Rhizophlyctidales

Abstract

Zoospore ultrastructural characters combined with molecular phylogenetic hypotheses have been used to revise the taxonomy of zoosporic true fungi. An example is the reclassification of Rhizophlyctis rosea-like fungal strains into four new families and three new genera within the order Rhizophlyctidales. One genus was Borealophlyctis, which included a Canadian isolate, DAOMC 229843. A recent survey of chytrid diversity in Alabama (USA) yielded additional strains (WJD 170, WJD 171) in the Borealophlyctis lineage. With light and transmission-electron microscopy we examined strains DAOMC 229843, WJD 170 and WJD 171. We also analyzed partial nuc 28S rDNA D1-D3 domains (28S) and nuc rDNA region encompassing the internal transcribed spacers 1 and 2 and 5.8S (ITS) sequences to determine the phylogenetic placement of the strains within Rhizophlyctidales. Based on molecular divergence and morphological differences from the type Borealophlyctis paxensis, we recognize DAOMC 229843, WJD 170 and WJD 171 as representatives of the new species Borealophlyctis nickersoniae.

• chytrid
• Chytridiomycota
• ecology
• morphology
• taxonomy

Acknowledgments

This study was supported by the National Science Foundation ( REVSYS DEB-00949305), the McNair Scholars Program and the Department of Biological Sciences of the University of Alabama. Access to the temporary pond was made possible by Walter H. Smith and permit No. 2660 from the United States Department of Agriculture Forest Service. Jonathan Antonetti aided in the collection of the temporary pond sample and Nikaela Yarbrough-Flournoy generously collected the sample from the cotton field. We thank the DAOMC for providing the strain DAOMC 229843 and Nancy L. Nickerson for isolating it. We thank P. Kirk and S. Penneycook for nomenclatural advice. We appreciate the anonymous reviewers and Joyce E. Longcore for their careful reviews and helpful suggestions.