Home • Testicularia cyperi MCA 3645 v1.0
Testiculatria cyperi smut balls on Rhynchospora sp. (left) and its culture on PDA (right)
Testiculatria cyperi smut balls on Rhynchospora sp. (left) and its culture on PDA (right). Bar on the right figure = 2. 5 mm. Photos: M. Catherine Aime (left) and Teeratas Kijpornyongpan (right).

Testicularia cyperi (MCA3645)

Testicularia cyperi Klotzsch was first described in 1832 (Klotzsch, 1832). The fungus colonizes developing ovules of Rhynchospora spp. (Cyperaceae) to produce hypertrophied galls. The isolate selected for genome sequencing (MCA3645) was grown on a potato dextrose agar (PDA) plate from an infected Rhynchospora species in Louisiana, and may represent the only known cultured strain of T. cyperi. In culture, the fungus initially forms white to cream yeast-like colonies, and becoming friable and yellow to tan in age with a filliform margin.

Testicularia species were traditionally classified in Cintractiaceae with Cintractia, Trichocintractia and related genera based on similar host plants, similarities in sorus development and basidial structure (Vánky, 2001). However, molecular phylogenetic analyses of several rDNA loci showed that Cintractiaceae was non-monophyletic (Begerow et al., 2006). Thus most members of Cintractiaceae were moved to other families (Begerow et al., 2006). However, due to a lack of molecular data, the genus Testicularia was not included in that study, and it is still designated as incertae sedis in modern classifications (Begerow et al., 2014).

The genome sequence of T. cyperi will provide the first whole genome reference sequence for a smut fungus in the Ustilaginales that is not in the Ustilaginaceae. Researchers will use these data in phylogenetic and phylogenomic reconstructions and in comparative genomics studies that seek to elucidate the molecular bases governing production of sexual and anamorphic states and the evolution of phytopathogenicity in Ustilaginomycotina.


Genome Reference(s)



Begerow D, Stoll M, Bauer R. 2006. A phylogenetic hypothesis of Ustilaginomycotina based on multiple gene analyses and morphological data. Mycologia 98(6):906–916.

Begerow D, Schäfer AM, Kellner R, Yurkov A, Kemler M, Oberwinler F, Bauer R. 2014. Ustilaginomycotina. PP 295–329 In: The Mycota. Vol. VII Part A. Systematics and Evolution. 2nd Ed. McLaughlin DJ, Spatafora JW (Eds.) Springer-Verlag, Berlin. 

Klotzsch JF. 1938. Testicularia. Linnaea 7:202.

Vánky. 2001. The emended Ustilaginaceae of the modern classificatory system for smut fungi. Fungal Diversity 6:131–147.