Special Interest Group Meeting

Species Delimitations and Evolutionary History of the Cladia aggregata Aggregate (Lecanorales, Ascomycota)

Sittiporn Parnmen¹,², Achariya Rangsiruji¹, Pachara Mongkolsuk², Kansri Boonpragob² & H. Thorsten Lumbsch³, ¹Department of Biology, Faculty of Science, Srinakharinwirot University, Bangkok, 10110, Thailand, ²RAMK Herbarium, Department of Biology, Faculty of Science, Ramkhamhaeng, University, Bangkok 10140, Thailand, ³Department of Botany, The Field Museum, 1400 S. Lake Shore Drive Chicago, IL 60605, USA

Cladia (Cladoniaceae) is a small genus of ca. 14 species with a center of distribution in the Southern Hemisphere. Within the family, the genus Cladia has received attention, since the species circumscription has been difficult based on enormous morphological and chemical diversity. Within the genus, the Cladia aggregata complex is considerably difficult and authors accepted one to seven species to classify the morphological and chemical diversity in this group. The aims of this study were to (i) test the phylogenetic placement of the Cladia aggregata aggregate within a monophyletic Cladia, and (ii) evaluate the species delimitation in the Cladia aggregata complex using molecular data. Phylogenetic relationships were reconstructed using a data set of nuclear ITS, LSU, mitochondrial SSU rDNA, and protein-coding Mcm7 sequences, while the relationships among samples of the C. aggregata aggregate were studied using nuclear ITS and protein-coding GAPDH sequences. We applied a cohesion species approach using haplotype networks to delimit species by rejecting the null hypothesis of a random distribution of traits in clades of the network. In addition we assessed gene flow among putative species identified by the cohesion species concept. We regard reproductive isolation of identified clades as additional evidence that they represent distinct species.