The Diagnostic Characteristics Are Highly Homoplasious Used in Cladonia gracilis and Cladonia cornuta

Abstract

The genus Cladonia lives on many different habitat and more than 400 species hitherto have been documented. Traditionally, the genus was classified into 7 taxonomic sections by morphology. However, the taxonomical classification is not well accord with that of molecular phylogenetic research. The genus has high morphological diversity, yet there has not been a coherent agreement on the delimitation of species. The Cladonia gracilis group and allies in the section Cladonia show an extreme phenotypic variety. Cladonia gracilis and Cladonia cornuta which are members of the C. gracilis group have been identified by variable characteristics. This study deals with the taxonomic problem between C. gracilis and C. cornuta by confirming the consistent phenotypic characteristics again with molecular phylogeny at species level. About 150 specimen were analyzed by 36 morphological and chemical characteristics using the DNA sequences with three loci(ITS rDNA, mtSSU and LSU rDNA). Specimen were collected from various regions covering bipolar areas and Korea. Phenotypic data will be discussed with several statistical methods. The study indicates that the homogeneous clade did not form in these species at species level. The results show no clear distinction between the two species in terms of secondary metabolites and geographical distribution. The characteristics used for classical diagnosis may be highly homoplasious.