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Food webs in temporary forest ponds are driven by decomposition of terrestrial inputs. Chytrid fungi are important components of the fungal community, degrading leaf litter in streams reliant on terrestrial inputs and in lake ecosystems where they may stabilize the food web. However, little is known about chytrid fungi in temporary forest ponds. We inventoried the chytrid diversity present in two temporary forest ponds via light microscopy of baited samples and ion semiconductor (Ion Torrent) sequencing of environmental DNA. We quantified trends of chytrid alpha and beta diversity as a function of spatial and temporal factors. A total of 59 chytrid taxa were detected throughout the study. Beta diversity exhibited variation across the sampled months for both the entire fungal community as well as for chytrids alone. Shifts in community composition were also apparent, although diversity metrics and composition patterns did not meet adjusted P values. The results of this study highlight the diversity of chytrid fungi in temporary forest ponds and the need for further studies on the spatial and temporal dynamics of chytrid species. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Many chytrid phylogenies contain lineages representing a lone taxon or a few organisms. One such lineage in recent molecular phylogenies of Rhizophydiales contained two marine chytrids, Rhizophydium littoreum and Rhizophydium aestuarii. To better understand the relationship between these organisms, we increased sampling such that the R. littoreum/R. aestuarii lineage included 10 strains of interest. To place this lineage in Rhizophydiales, we constructed a molecular phylogeny from partial nuc 28S rDNA D1-D3 domains (28S) of these and 80 additional strains in Rhizophydiales and examined thallus morphology and zoospore ultrastructure of our strains of interest. We also analyzed sequences of the nuc rDNA region encompassing the internal transcribed spacers 1 and 2, along with the 5.8S rDNA (ITS) of our 10 strains of interest to assess sequence similarity and phylogenetic placement of strains within the lineage. The 10 strains grouped together in three well supported clades: (i) Rhizophydium littoreum + Phlyctochytrium mangrovei, (ii) three strains of Rhizophydium aestuarii and (iii) five previously unidentified strains. Light microscopic observations revealed four distinct thallus morphologies, and zoospore ultrastructural analyses revealed four distinct constellations of ultrastructural features. On the bases of morphological, ultrastructural and molecular evidence we place these strains in the new family Halomycetaceae and four new genera (Halomyces, Paludomyces, Ulkenomyces, Paranamyces) in Rhizophydiales. [ABSTRACT FROM AUTHOR]

Chytriomyces is a complex genus in Chytridiales. The morphological concept of the genus expanded as new taxa were added, and studies of zoospore ultrastructure and molecular phylogenies have revealed the genus to be polyphyletic. One problematic taxon is C. spinosus Fay, a distinctive species characterized by whorls of spines on the zoosporangium and a large accumulation of vesicle material beneath the operculum. With light-, scanningelectron and transmission-electron microscopy, we examined a culture (WJD186) isolated from a muck sample collected from a temporary forest pond. We also analyzed the D1-D2 variable domains of the nuc 28S rDNA (28S) sequences to confirmthe phylogenetic placement of the species relative to the type of Chytriomyces, C. hyalinus Karling. The morphology of culture WJD186 is consistent with features Fay described for C. spinosus, and the zoospore ultrastructure is consistent with the Group I-type zoospore characters of Chytriomycetaceae (Chytridiales). In our molecular phylogeny C. spinosus does not group with the type of Chytriomyces. Consequently, we erect a new genus in Chytriomycetaceae and present the new combination Fayochytriomyces spinosus. [ABSTRACT FROM AUTHOR]

Alabama is a biodiversity hotspot. The diversity of chytrid fungi, however, is underexplored. For this reason, we used standard bait-culturing techniques to sample habitats in Tuscaloosa County for chytrids. We cultured 100 isolates; the majority was assigned to 23 taxa belonging to 6 of the 7 recognized orders. Some could not be assigned to a currently described taxon. The majority of isolates belonged to one of three taxa: Chytriomyces hyalinus, Rhizoclosmatium globosum, and Boothiomyces macroporosum. This result demonstrates that chytrid communities in Tuscaloosa County, as elsewhere, are composed of a few common and many uncommon to rare taxa. The presence of unidentified chytrid isolates demonstrates the need for further sampling in Alabama, and the potential for this sampling to broaden our understanding of chytrid diversity. [ABSTRACT FROM AUTHOR]

Abstract The purpose of our research is to investigate morphology, zoospore ultrastructure, and molecular placement of six strains in the Asterophlyctis (Chytridiales) lineage. In previous molecular analyses strain JEL 186, putatively Asterophlyctis sarcoptoides , placed as basal in family Chytriomycetaceae. Recent sampling for chytrids resulted in isolation of five strains (WJD 209, MP 058, JEL 524, JEL 857, and JEL 885) molecularly related to strain JEL 186. Our morphological evaluations reveal that strains JEL 186 and WJD 209 are members of Asterophlyctis. Strain WJD 209 is considered representative of the type, A. sarcoptoides , and strain JEL 186 a new species, Asterophlyctis michiganensis. The four strains MP 058, JEL 524, JEL 857, and JEL 885 are distinct from Asterophlyctis , and we consider them as members of a new genus, Wheelerophlyctis , composed of two species, Wheelerophlyctis interior and Wheelerophlyctis interiexterior. Asterophlyctis and Wheelerophlyctis are sister taxa and we demarcate that lineage as Asterophlyctaceae. The two genera also have similar zoospore ultrastructure, which is unique among strains in Chytridiales. In consideration of their molecular position and zoospore ultrastructure, we hypothesize that Asterophlyctis and Wheelerophlyctis represent a bridge between Chytriomycetaceae and Chytridiaceae. This research expands our concepts of systematics and zoospore ultrastructural variation in Chytridiales. [ABSTRACT FROM AUTHOR]