Filling a gap in the taxonomy of phyllachoroid fungi: Proposition of Neopolystigma, gen. nov., and the new family Neopolystigmataceae

ABSTRACT

A Polystigma-like found on an herbaceous to shrubby species of Fabaceae (Andira humilis) in the Brazilian Cerrado was morphologically close to Polystigma pusillum, a leaf parasite on Andira inermis collected in Central America and Brazil. Phylogenetic analyses using a combination of the rDNA 28S, 18S, and internal transcribed spacer (ITS) regions placed both fungi in the Phyllachorales, and not in Polystigamataceae/Xylariales, where Polystigma species belong, and characteristically found on members of the Rosaceae, causing red leaf blotch containing bright-colored fungal stromata spread on the lesions. This disease prevails in orchards in the Northern Hemisphere, infecting Amygdalus, Cerasus, Padus, and Prunus species, but never in the Tropics. Polystigma species infecting other botanical families have been reallocated in different families, orders, and even classes in Ascomycota. In our phylogenetic analyses, the two species on Andira were allocated in Phyllachorales but separated in a well-supported cluster from Phyllachoraceae and Phaeochoraceae. In relation to Telimenaceae, the statistical support is not strong; however, considering that its type genus, Telimena, was never sequenced, we choose to accept Neopolystigma (type N. saraivae) as the type genus of a new family, Neopolystigmataceae. The sister species of N. saraivae, Polystigma pusillum found on A. inermis, was recombined into N. pusillum.

KEYWORDS:

• Andira humilis
• Andira inermis
• Brazil
• Cerrado
• Phyllachorales
• Polystigma
• Polystigmataceae
• Stigmatula
• Xylariales
• 4 new taxa

ACKNOWLEDGMENTS

The authors expressed their gratitude to Prof. Mariza Sanchez (in memoriam) for assistance and dedication to the Mycological Collection of the Herbarium UB for almost 25 years. The authors thank Prof. Norman W. Schaad, a native English speaker, for reviewing the manuscript.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors thank CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior/Ministry of Education-Brazil) for a DSc fellowship to D.C.G. and CNPQ PPBIO/CERRADO/2012 for a DSc fellowship to M.D.M.S. J.C.D. received financial support from the Fundação de Apoio à Pesquisa do Distrito Federal (FAP-DF) through project FAP-DF 00193-077/2019-41, headed by Prof. Dirceu Macagnan, and from CNPq/MCTI-Brazil-PPBIO-Cerrado-2012/2016.