Pachara Mongkolsuk

Using Phylogenetic and Coalescent Methods to Understand the Species Diversity in the Cladia aggregata Complex (Ascomycota, Lecanorales)

The Cladia aggregata complex is one of the phenotypically most variable groups in lichenized fungi, making species determination difficult and resulting in different classifications accepting between one to eight species. Multi-locus DNA sequence data provide an avenue to test species delimitation scenarios using genealogical and coalescent methods, employing gene and species trees. Here we tested species delimitation in the complex using molecular data of four loci (nuITS and IGS rDNA, protein-coding GAPDH and Mcm-7), including 474 newly generated sequences. Using a combination of ML and Bayesian gene tree topologies, species tree inferences, coalescent-based species delimitation, and examination of phenotypic variation we assessed the circumscription of lineages. We propose that results from our analyses support a 12 species delimitation scenario, suggesting that there is a high level of species diversity in the complex. Morphological and chemical characters often do not characterize lineages but show some degree of plasticity within at least some of the clades. However, clades can often be characterized by a combination of several phenotypical characters. In contrast to the amount of homoplasy in the morphological characters, the data set exhibits some geographical patterns with putative species having distribution patterns, such as austral, Australasian or being endemic to Australia, New Zealand or Tasmania.

Diversity and phylogenetic survey of cyanobacterial lichens (Collematineae, Ascomycota) in mangrove forests of eastern Thailand

Abstract Peltigeralean lichenized fungi were surveyed in the mangroves of Trat Province at the eastern coast of Thailand. Eleven species were found belonging to the genera Coccocarpia, Lepidocollema, Leptogium and Physma. Among them, the genus Coccocarpia was most abundant and diverse. Lepidocollema wainioi was also recorded here from Thailand for the first time. Based on the current classification of the peltigeralean fungi the phylogenetic placement of the suborder Collematineae was evaluated using a combined dataset of nuclear ITS and mitochondrial SSU rDNA sequences. Phylogenetic analyses using maximum likelihood and Bayesian approaches revealed issues with the species delimitation in the genera Coccocarpia and Lepidocollema, where the data indicated non-monophyletic lineages. Additional studies with extended sampling will be necessary to address species boundaries in these lichens.