Research Article |
Corresponding author: Tine Grebenc ( tine.grebenc@gozdis.si ) Academic editor: Alfredo Vizzini
© 2020 Marcelo A. Sulzbacher, Takamichi Orihara, Tine Grebenc, Felipe Wartchow, Matthew E. Smith, María P. Martín, Admir J. Giachini, Iuri G. Baseia.
This is an open access article distributed under the terms of the CC0 Public Domain Dedication.
Citation:
Sulzbacher MA, Orihara T, Grebenc T, Wartchow F, Smith ME, Martín MP, Giachini AJ, Baseia IG (2020) Longistriata flava (Boletaceae, Basidiomycota) – a new monotypic sequestrate genus and species from Brazilian Atlantic Forest. MycoKeys 62: 53-73. https://doi.org/10.3897/mycokeys.62.39699
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A new monotypic sequestrate genus, Longistriata is described based on collections from the Neotropical forest of Atlantic forest in Paraíba, Northeast Brazil – an area known for its high degree of endemism. The striking features of this new fungus are the hypogeous habit, the vivid yellow peridium in mature basidiomes, broadly ellipsoid basidiospores with a distinct wall that is ornamented with longitudinal striations and lageniform cystidia with rounded apices. Phylogenetic analysis, based on LSU and tef-1α regions, showed that the type species, Longistriata flava, is phylogenetically sister to the monotypic sequestrate African genus Mackintoshia in Boletaceae. Together these two species formed the earliest diverging lineage in the subfamily Zangioideae. Longistriata flava is found in nutrient-poor white sand habitats where plants in the genera Coccoloba (Polygonaceae) and Guapira (Nyctaginaceae) are the only potential ectomycorrhizal host symbionts.
Boletales, ITS, phylogeny, sequestrate fungi, taxonomy, tropical forest.
Fungi in the order Boletales (Agaricomycetes, Basidiomycota) comprise a morphological diverse group including agaricoid, boletoid, gasteroid, secotioid, corticioid, merulioid, hydroid and polyporoid forms (
Sequestrate Boletaceae have been described from across the globe with records from all continents except Antarctica but relatively little is known about sequestrate boletoid fungi in South America (
In Brazil, there are numerous surveys that have documented epigeous Boletales in exotic plantations and native forests (
As part of recent studies on ectomycorrhizal and sequestrate fungi in northeastern Brazil (
Specimens were collected in survey missions targeting sequestrate fungi during the rainy seasons of 2011–2013 (
Fungal DNA was extracted from fresh specimens (
Suppl. material
Bayesian analyses were conducted with MrBayes 3.2 (
Maximum likelihood (ML) analyses were conducted with RAxML 8.2.10 (
The nLSU + TEF1 combined dataset consisted of 85 taxa and 2,014 aligned nucleotide positions. The Bayesian inference reached convergence after 4.6M generations. We therefore discarded the first 4,600 trees in each chain, and the remaining 5,401 trees in each chain were summarized to approximate Bayesian posterior probabilities (PPs). ESS of all the model parameters were sufficiently large (>200). The total arithmetic and harmonic means of Likelihoods (lnL) were -29,498.16 and -29,562.71, respectively. In RAxML analysis the log likelihood of the ML tree was -29,121.825209.
The nLSU + TEF1 combined tree of the Boletaceae supported our hypothesis that the sequestrate basidiomes of the vivid yellow fungus belong to an undescribed genus in the Boletaceae (Fig.
Longis (Latin), with or from the long; striatus (Latin), striate, fluted; in reference to the distinctive series of thin longitudinal striations on the surface of the basidiospores.
Distinguished from other genera in Boletaceae by a combination of the following characters: Basidiomata hypogeous to subhypogeous, sequestrate, subglobose, with a short stipe (Fig.
Longistriata flava Sulzbacher, Orihara, Grebenc, M.P. Martín & Baseia, sp. nov.
Flavus (Latin), refers to the yellow peridium of the species.
Holotype: Brazil, Paraíba State, Mamanguape, Guaribas Biological Reserve, 06°44.545'S, 35°08.535'W, 14.VII.2012, leg. Sulzbacher–393 (
Basidiomata hypogeous to subhypogeous, 11–24 mm wide, 13–16 mm high; subglobose, depressed subglobose to oblong in older stages, with small folds at the base; with a short stipe (Fig.
A–G Longistriata flava (
Peridium 100–200 µm thick, composed by a cutis of interwoven hyphae and immersed in a gelatinized matrix (Fig.
A–D Basidiospores of Longistriata flava (
Hypogeous to subhypogeous, solitary or scattered, under fallen leaves or in O1 soil horizon, in sandy soil, among trees in Brazil’s Atlantic rainforest, in vicinity of Coccoloba alnifolia Casar., C. laevis Casar. (Polygonaceae) and species of Guapira Aubl. (Nyctaginaceae). Species in both plant genera (Coccoloba and Guapira) have been consistently confirmed as ectomycorrhizal hosts throughout the Neotropics (
Known only from the type locality.
Brazil, Paraíba State, Mamanguape, Guaribas Biological Reserve, 06°44.545'S, 35°08.535'W, 27.VII.2012, leg. Sulzbacher–466 (paratype
The specimens
Longistriata is a striking new monotypic genus described from the Atlantic forest in the Northeastern part of Brazil. The only known representative of the genus is the newly described Longistriata flava. This species is characterized by the hypogeous habit, a smooth and bright yellow peridium (Fig.
In addition to Longistriata several other genera of sequestrate Boletaceae, Chamonixia, Rossbeevera, Rhodactina, and Turmalinea, also have basidiospores with longitudinal ridges. However, members of these genera all differ in the shape and number of ridges. Rosbeevera has ellipsoid to fusiform basidiospores with 3–5 ridges (
The hypogeous habit, shape of basidiomes (e.g. globose, subglobose, tuberiform) and the rudimentary sterile base in L. flava suggest a possible relationship with the sequestrate truffle-like genus Octaviania (
The phylogenetic analyses suggest that the new Brazilian genus is closely related to several genera in the subfamily Zangioideae that also have bright yellow colors at the base of the stipe (e.g. Chiua Yan C. Li & Zhu L. Yang, Harrya Halling, Nuhn & Osmudson, Royoungia Castellano, Trappe & Malajczuk, and Zangia Yan C. Li & Zhu L. Yang) (
Several other sequestrate Boletaceae are similar to L. flava, either in their morphology or in their tropical distribution. Members of the sequestrate genus Mycoamaranthus Castellano, Trappe & Malajczuk also produce bright yellow basidiomata and belong to Boletaceae (
Unfortunately, we have not yet confirmed the ECM status of Longistriata flava based on sequences from ECM root tips from native Brazilian trees. However, basidiomes of Longistriata have always been collected in the lowland semi-deciduous forest to savanna known as “tabuleiro” in close proximity to woody plants in the ECM genera Coccoloba (Polygonaceae) and Guapira (Nyctaginaceae). Given that ECM plants in these genera are known to host a wide array of ECM fungi from other sites in tropical South America (Tedersoo et al. 2010;
The authors wish to thank Dr. Jomar G. Jardim for identifying tree species in the Guaribas Biological Reserve. This study is in part a result of the Ph.D. thesis of Marcelo A. Sulzbacher, with a scholarship provided by the Brazilian Government (CAPES). The work was partially supported by CNPq project PVE 407474/2013-7 and co-financed by the Brazil-Slovenia bilateral project (BI-BR/11-13-005(SRA) / 490648/2010-0 (CNPq)), research project J4-1766 “Methodology approaches in genome-based diversity and ecological plasticity study of truffles from their natural distribution areas” and the Research Program in Forest Biology, Ecology and Technology (P4-0107) of the Slovenian Research Agency.
Table S1. Specimens and sequences used for the molecular phylogenetic analyses (i. e., the nLSU + TEF1 combined dataset) and ITS sequence comparison.
Data type: molecular data