The Lichenologist 42(4): 1–12 (2010) © British Society, 2009 doi:10.1017/S0024282909990739

A discussion about reproductive modes of furfuracea based on phylogenetic data

Zuzana FERENCOVA, Ruth DEL PRADO, Israel PÉREZ-VARGAS, Consuelo HERNÁNDEZ-PADRÓN and Ana CRESPO

Abstract: Two asexual reproductive strategies of the common lichen Pseudevernia furfuracea are described. Although the species propagates mainly by isidia, some specimens also show the develop- ment of soralia. Morphological, chemical and molecular analyses were performed on three such sorediate specimens from the Canary Islands, Morocco and Turkey. Maximum parsimony, maximum likelihood and Bayesian analyses indicate that: a) sorediate samples represent only a morphological variant of the reproductive mode and b) the separation of taxa (at species level or below) on the basis of their containing either olivetoric acid or physodic and oxyphysodic acids is not appropriate. In addition, a phylogenetic reconstruction of the genus Pseudevernia is presented for the first time. The tree shows two sister monophyletic clades, one containing American species (P. intensa, P. cladonia, P. consocians), and the second encompassing the P. furfuracea samples (including sorediate specimens). The biological and taxonomical significance of soralia in sorediate samples is discussed. Keywords: isidia, soredia, vegetative modes, , species pairs,

Introduction fertile without vegetative propagules (pri- Lichens are stable symbiotic organisms in mary species) and the other with soredia or which only the fungal partner is able to carry isidia (secondary species); the latter being out sexual reproduction. The development derived from the former. Hale (1965) pre- of special dispersal structures containing sumed in his work on Parmelia (subgenus both symbionts, such as soredia or isidia, Amphigymnia) that sorediate species evolved together with thallus fragmentation, allow from either isidiate or nonsorediate– the efficient propagation of the symbiotic nonisidiate ancestors, naming the two or dual organism. Soredia have been inter- three taxa involved ‘counterparts’. preted as being vegetative propagules se- The classic interpretation among li- lected for during the evolutionary history of chenologists supports taxonomic separation lichens (Poelt 1970, 1972) and have been at the species level for both members of a accorded significant status as taxonomic species pair. However, studies based on characters. Earlier investigations defined morphological and ecological information ‘species pairs’ in lichens as two species, one (Tehler 1982) or phylogenetic analysis (Lohtander et al. 1998a, b; Myllys et al. 1999, 2001; Articus et al. 2002; Molina et al. 2002; Cubero et al. 2004; Buschbom & Mueller Z. Ferencova, R. Del prado and A. Crespo (correspond- ing author): Departamento de Biologı´a Vegetal II, 2006) show, at least for sorediate/ Facultad de Farmacia, Universidad Complutense de nonsorediate species pairs, that these forms Madrid, E-28040 Madrid, . Email: do not separate into monophyletic lineages. [email protected] Consequently, pairs have been interpreted as I. Pérez-Vargas and C. Hernández-Padrón: Departa- mento de Biologı´a Vegetal, Facultad de Farmacia, Uni- representing two dispersal strategies and the versidad de La Laguna, E-38071, La Laguna, Tenerife, specific status of each member of the pair has Canary Islands, Spain. not been corroborated. Few cases of isidiate/