Elucidating species richness in lichen fungi: The genus <i>Sticta</i> (Ascomycota: Peltigeraceae) in Puerto Rico

Mercado‐Díaz, Joel A.; Lücking, Robert; Moncada, Bibiana; Widhelm, Todd J.; Lumbsch, H. Thorsten

doi:10.1002/tax.12320

Cited by 15 publications

(28 citation statements)

References 133 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While reciprocal monophyly as an exclusivity criterion for species delimitation is intuitively appealing, metapopulation lineages may not be recovered as monophyletic of a number of reasons (Knowles and Carstens 2007), including incomplete lineage sorting in recently diverged species, introgression and hybridization (see below), porous or "semi-permeable" species boundaries, and other evolutionary scenarios (Joly et al 2009;Steenkamp et al 2018). Therefore, emerging lineages nested within a paraphyletic residual have been accepted as recently evolving species under certain circumstances (Wheeler and Nixon 1990;Crisp and Chandler 1996;Wheeler and Platnik 2000;Funk and Omland 2003;Freudenstein et al 2017;Mercado-Díaz et al 2020). It is further expected that diverging lineages also diverge in phenotype, including morphology, anatomy, chemistry, metabolism, and physiology, owing to either neutral mechanisms such as genetic drift, selective forces in diverging environments, selecting of sexual partners, or hybridization (Cohan and Hoffmann 1989;Harrington and Rizzo 1999;Grube and Kroken 2000;McGuigan et al 2005;Pfennig et al 2007;Mercader et al 2009;Schoustra et al 2012;Vigoder et al 2015;Ament-Velásquez et al 2020).…”

Section: Species Concepts and Their Application In Lichenized Fungimentioning

confidence: 99%

Species in lichen-forming fungi: balancing between conceptual and practical considerations, and between phenotype and phylogenomics

2021

Self Cite

View full text Add to dashboard Cite

Lichens are symbiotic associations resulting from interactions among fungi (primary and secondary mycobionts), algae and/or cyanobacteria (primary and secondary photobionts), and specific elements of the bacterial microbiome associated with the lichen thallus. The question of what is a species, both concerning the lichen as a whole and its main fungal component, the primary mycobiont, has faced many challenges throughout history and has reached new dimensions with the advent of molecular phylogenetics and phylogenomics. In this paper, we briefly revise the definition of lichens and the scientific and vernacular naming conventions, concluding that the scientific, Latinized name usually associated with lichens invariably refers to the primary mycobiont, whereas the vernacular name encompasses the entire lichen. Although the same lichen mycobiont may produce different phenotypes when associating with different photobionts or growing in axenic culture, this discrete variation does not warrant the application of different scientific names, but must follow the principle "one fungus = one name". Instead, broadly agreed informal designations should be used for such discrete morphologies, such as chloromorph and cyanomorph for lichens formed by the same mycobiont but with either green algae or cyanobacteria. The taxonomic recognition of species in lichen-forming fungi is not different from other fungi and conceptual and nomenclatural approaches follow the same principles. We identify a number of current challenges and provide recommendations to address these. Species delimitation in lichen-forming fungi should not be tailored to particular species concepts but instead be derived from empirical evidence, applying one or several of the following principles in what we call the LPR approach: lineage (L) coherence vs. divergence (phylogenetic component), phenotype (P) coherence vs. divergence (morphological component), and/or reproductive (R) compatibility vs. isolation (biological component). Species hypotheses can be established based on either L or P, then using either P or L (plus R) to corroborate them. The reliability of species hypotheses depends not only on the nature and number of characters but also on the context: the closer the relationship and/or similarity between species, the higher the number of characters and/or specimens that should be analyzed to provide reliable delimitations. Alpha taxonomy should follow scientific evidence and an evolutionary framework but should also offer alternative practical solutions, as long as these are scientifically defendable. Taxa that are delimited phylogenetically but not readily identifiable in the field, or are genuinely cryptic, should not be rejected due to the inaccessibility of proper tools. Instead, they can be provisionally treated as undifferentiated complexes for purposes that do not require precise determinations. The application of infraspecific (gamma) taxonomy should be restricted to cases where there is a biological rationale, i.e., lineages of a species complex that show limited phylogenetic divergence but no evidence of reproductive isolation. Gamma taxonomy should not be used to denote discrete phenotypical variation or ecotypes not warranting the distinction at species level. We revise the species pair concept in lichen-forming fungi, which recognizes sexually and asexually reproducing morphs with the same underlying phenotype as different species. We conclude that in most cases this concept does not hold, but the actual situation is complex and not necessarily correlated with reproductive strategy. In cases where no molecular data are available or where single or multi-marker approaches do not provide resolution, we recommend maintaining species pairs until molecular or phylogenomic data are available. This recommendation is based on the example of the species pair Usnea aurantiacoatra vs. U. antarctica, which can only be resolved with phylogenomic approaches, such as microsatellites or RADseq. Overall, we consider that species delimitation in lichen-forming fungi has advanced dramatically over the past three decades, resulting in a solid framework, but that empirical evidence is still missing for many taxa. Therefore, while phylogenomic approaches focusing on particular examples will be increasingly employed to resolve difficult species complexes, broad screening using single barcoding markers will aid in placing as many taxa as possible into a molecular matrix. We provide a practical protocol how to assess and formally treat taxonomic novelties. While this paper focuses on lichen fungi, many of the aspects discussed herein apply generally to fungal taxonomy. The new combination Arthonia minor (Lücking) Lücking comb. et stat. nov. (Bas.: Arthonia cyanea f. minor Lücking) is proposed.

show abstract

Section: Species Concepts and Their Application In Lichenized Fungimentioning

confidence: 99%

Species in lichen-forming fungi: balancing between conceptual and practical considerations, and between phenotype and phylogenomics

2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…Lobes are variously indented (Galloway, 1994(Galloway, , 1997(Galloway, , 2007Moncada, 2012;Moncada & Lücking, 2012;Moncada et al, 2014b). Until now, more than 200 species of Sticta have been described (Moncada & Lücking, 2012;Moncada et al, 2013aMoncada et al, , 2013bMoncada et al, , 2020Moncada et al, , 2021aMoncada et al, , 2021bLücking et al, 2017;Mercado-Díaz et al, 2020), but according to Moncada et al (2013bMoncada et al ( , 2021b the number of species belonging to this genus is more than twice as high. The discrepancy between the described and the potential number of Sticta species is related to the fact that in many countries no detailed studies have been undertaken.…”

Section: Introductionmentioning

confidence: 99%

“…The discrepancy between the described and the potential number of Sticta species is related to the fact that in many countries no detailed studies have been undertaken. For example, recent research conducted on Sticta in Puerto Rico revealed the presence of more than ten taxa potentially endemic to that island (Mercado-Díaz et al, 2020). Bolivia, conversely, is one of the relatively understudied countries in term of the presence of Sticta species.…”

Section: Introductionmentioning

confidence: 99%

First records of Sticta weigelii s.str. from Bolivia confirmed by molecular data

Ossowska

2021

Folia Cryptog. Estonica

View full text Add to dashboard Cite

The first records of Sticta weigelii s.str. from Bolivia confirmed by molecular data are presented. The species is characterized by the presence of marginal isidia, which are darker than the thallus, usually cylindrical (not flattened), thin, dark brown to black lower tomentum and often partly yellow cyphellae. Previously, the presence of S. weigelii in Bolivia was based only on a morphological concept, encompassing various unrelated species, whereas the occurrence of S. weigelii s.str. was uncertain.

show abstract

“…This species belongs to the apparently pantropical Sticta ciliata complex which appears to contain several recently-diverged, phenotypically cryptic lineages (Magain & Sérusiaux 2015; Mercado-Díaz et al 2020; Moncada et al 2020). Species of this clade resemble S. fuliginosa with respect to their rounded lobes with laminal isidia but are much smaller overall and are consistently set apart by the conspicuous, white marginal cilia.…”

Section: The Speciesmentioning

confidence: 99%

A taxonomic reassessment of the genusSticta(lichenized Ascomycota:Peltigeraceae) in the Hawaiian archipelago

2021

Self Cite

View full text Add to dashboard Cite

The taxonomy of the genus Sticta in Hawaii is reassessed, based on a separately published molecular phylogeny using the fungal barcoding marker ITS. Based on Magnusson and Zahlbruckner's treatment from 1943 and Magnusson's catalogue from 1955, seven species of Sticta and three infraspecific taxa had been reported from the archipelago, all widespread except the putative endemic S. plumbicolor. Here we provide a taxonomic treatment of 13 taxa, 12 species and one subspecies, distinguished in a previous phylogenetic analysis: S. acyphellata, S. andina, S. antoniana, S. emmanueliana, S. flynnii, S. fuliginosa, S. hawaiiensis, S. limbata, S. plumbicolor, S. scabrosa subsp. hawaiiensis, S. smithii, S. tomentosa and S. waikamoi. All taxa are described, discussed and illustrated and a dichotomous key is presented. The implications of revised species taxonomies for studies in other fields such as ecology, ecophysiology, biogeography, biochemistry, and applications such as environmental monitoring are discussed. We also propose a protocol to use Sticta lichens to monitor the environmental health of Hawaiian ecosystems.

show abstract

Elucidating species richness in lichen fungi: The genus Sticta (Ascomycota: Peltigeraceae) in Puerto Rico

Cited by 15 publications

References 133 publications

Species in lichen-forming fungi: balancing between conceptual and practical considerations, and between phenotype and phylogenomics

Species in lichen-forming fungi: balancing between conceptual and practical considerations, and between phenotype and phylogenomics

First records of Sticta weigelii s.str. from Bolivia confirmed by molecular data

A taxonomic reassessment of the genusSticta(lichenized Ascomycota:Peltigeraceae) in the Hawaiian archipelago

Contact Info

Product

Resources

About