Reinstatement and phylogenetic allocation of the palm rust genus Cerradoa in the Pucciniaceae, and establishment of Pseudocerradoa, gen. nov.

ABSTRACT

The genus Cerradoa (type species Cerradoa palmaea) was established in 1978 by Hennen and Ono and named after the Brazilian Cerrado biome. The holotype collected in Planaltina, Federal District, Brazil, belonged to the first rust fungus reported on palms (Arecaceae). For decades, the status of Cerradoa as a distinct genus has been regarded as doubtful, representing a synonym of Edythea (Uropyxidaceae) starting with the second edition of the Illustrated Genera of Rust Fungi in 1983. Our molecular phylogenetic analyses, as well as our morphological investigations, allowed us to reject this synonymy, leading to the reinstatement of Cerradoa within the Pucciniaceae. Cerradoa, together with morphologically similar genera such as the newly established Pseudocerradoa with two species (Ps. paullula and Ps. rhaphidophorae) infecting araceous hosts, the fern rust Desmella, and also P. engleriana, could not be assigned to any of the seven identified major lineages within the Pucciniaceae. Edythea, instead of being maintained as a member of the Uropyxidaceae, was herein placed in Pucciniaceae, shown phylogenetically in close relationship to Cumminsiella mirabilissima, both infecting the Berberidaceae. Additionally, our extensive phylogenetic analyses add guidance for future taxonomic revisions in the highly polyphyletic genus Puccinia and other established taxa within the family Pucciniaceae.

KEYWORDS:

• Brazil
• Cerrado fungi
• Edythea
• gap coding
• molecular phylogeny
• Neotropical Pucciniales
• Pucciniaceae
• rust fungi
• 3 new taxa

ACKNOWLEDGMENTS

The authors are grateful to Prof. Mariza Sanchez (in memoriam) for assistance and dedication to the Mycological Collection of the Herbarium UB for almost 25 years. J.C.D. thanks Dr. Gregory E. Shaner, when as curator of the Arthur Fungarium, Purdue University, for the loan of the type material of C. palmaea; both Dr. Christiane Ceriani Aparecido (curator of Herbarium IBI) and Dr. Marcelo Eiras for the loan of the rust-infected Lygodium specimens deposited at IBI; and Dr. Susan Lutz, US National Herbarium, for the image of Lygodium venustum (syn. L. polymorphum).

SUPPLEMENTARY MATERIAL

Supplemental data for this article can be accessed on the publisher’s Web site.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

Additional information

Funding

M.E. was financially supported by Ruhr University Bochum through grant RUB Researchschool PLUS B-2018-03-005. 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. Thanks are due to CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico, MCTI, Brazil) for doctorate fellowships to M.D.M.S. and CAPES (Coordenação de Aperfeiçoamento de Pesoal de Nível Superior, Ministério da Educação-Brazil) for doctorate fellowships to E.S.C.S. and S.G.-E.