A Molecular Phylogeny and a New Classification of Parmelioid Lichens Con- Taining Xanthoparmelia-Type Lichenan (Ascomycota: Lecanorales)
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53 (4) • November 2004: 959–975 Blanco & al. • Molecular phylogeny of parmelioid lichens A molecular phylogeny and a new classification of parmelioid lichens con- taining Xanthoparmelia-type lichenan (Ascomycota: Lecanorales) Oscar Blanco1, Ana Crespo1, John A. Elix2, David L. Hawksworth1 & H. Thorsten Lumbsch3 1 Departamento de Biología Vegetal II, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid 28040, Spain. [email protected], [email protected], [email protected] 2 Australian National University, Department of Chemistry, Faculty of Sciences, Canberra, ACT 0200, Australia. [email protected] 3 Department of Botany, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, Illinois 60605, U.S.A. [email protected] Generic concepts in the parmelioid lichens have been discussed intensively over the past three decades with- out reaching a broad consensus. We have now employed molecular data from three genes to provide a basis for a revised generic concept of the parmelioid lichens containing Xanthoparmelia-type lichenan. The phy- logeny of the parmelioid lichens containing Xanthoparmelia-type lichenan was reconstructed using a com- bined Bayesian analysis of nuclear ITS, LSU rDNA and mitochondrial SSU rDNA sequences, and a maximum parsimony analysis was also made for comparison. 179 new partial sequences of 58 taxa were generated and 12 sequences were downloaded from GenBank. Our results indicate that the lichens containing Xanthoparmelia-type lichenan form a monophyletic group. However, the segregates proposed earlier do not form distinct clades within the group. Alternative hypotheses of monophyletic Karoowia and Neofuscelia that are not nested within Xanthoparmelia were rejected with our dataset; Karoowia is polyphyletic, and Neofuscelia is reduced to synonymy under Xanthoparmelia. Xanthomaculina convoluta also belongs to Xanthoparmelia. Since we were unable to sequence the umbilicate type species of Xanthomaculina, we refrain from synonymizing that genus with Xanthoparmelia here. The synonymy of Chondropsis and Paraparmelia under Xanthoparmelia already proposed is supported. The revised and enlarged genus Xanthoparmelia includes species that have cell walls with Xanthoparmelia-type lichenan, a palisade plectenchyma with a pored epicortex, lack pseudocyphellae, with usually simple rhizines, generally bifusiform conidia, and medullary chemical diversity. Ten new names are proposed, and 129 new combinations are made into Xanthoparmelia. KEYWORDS: Bayesian statistics, combined analysis, Chondropsis, Karoowia, Neofuscelia, Paraparmelia, Parmelia, Parmeliaceae, phylogeny, Xanthomaculina, Xanthoparmelia. have recognized the new genera proposed in recent INTRODUCTION decades in this family by M. E. Hale and others, they Perhaps in no other group of lichenized ascomycetes have not been fully accepted by numerous European has the generic concept been so vigorously debated as in workers (e.g., Poelt & Vezda, 1981; Santesson, 1984; the parmelioid lichens. The generic concepts in lichen- Clauzade & Roux, 1986; Eriksson & Hawksworth, 1986, forming fungi in general have been in a state of flux since 1992, 1998; Purvis & al. 1992; Nimis, 1993; Llimona & the late 1960s (Nimis, 1998; DePriest, 1999; Rambold & Hladun, 2001). Triebel, 1999). While in crustose groups, ascomatal char- Xanthoparmelia (Hale, 1974, 1990; Elix & al., acter, such as ascus-type, ascoma and ascospore devel- 1986a) is the largest genus of foliose lichens worldwide; opment, and hamathecial characters, are utilized to cir- it includes more than 600 species and is recognized by cumscribe segregate genera, these characters are rela- the presence of usnic or isousnic acid in the upper cortex tively uniform or cryptic in the family Parmeliaceae, and hence a yellowish-green colour, and the polysaccha- which includes mainly macrolichens. The parmelioid ride Xanthoparmelia-type lichenan in the hyphal cell lichens in Parmeliaceae encompass both foliose to sub- walls (Elix, 1993, 1994). The genus is characterized by a crustose species, in total approximately 1500 taxa (Hale lack of pseudocyphellae, mainly simple rhizines, eciliate & DePriest, 1999). In view of the shortage of other char- lobes, short bifusiform (4–9 µm) or rarely bacilliform acters, vegetative morphological and chemical characters (4–14 µm) conidia, an upper cortex consisting of pal- have generally been employed to segregate genera in isade plectenchyma with a pored epicortex, and rather these lichens. While most non-European lichenologists high medullary chemical diversity. Most species occur 959.