Taxonomic study of three new Antarctic Asterochloris (Trebouxiophyceae) based on morphological and molecular data

  • Kim, Jong Im (Department of Biology, Chungnam National University) ;
  • Kim, Yong Jun (Department of Biology, Chungnam National University) ;
  • Nam, Seung Won (Nakdonggang National Institute of Biological Resources) ;
  • So, Jae Eun (Division of Polar Life Sciences, Korea Polar Research Institute) ;
  • Hong, Soon Gyu (Division of Polar Life Sciences, Korea Polar Research Institute) ;
  • Choi, Han-Gu (Division of Polar Life Sciences, Korea Polar Research Institute) ;
  • Shin, Woongghi (Department of Biology, Chungnam National University)
  • Received : 2019.11.07
  • Accepted : 2020.02.23
  • Published : 2020.03.15


Asterochloris is one of the most common genera of lichen phycobionts in Trebouxiophyceae. Asterochloris phycobionts associated with the lichenized fungi Cladonia and Stereocaulon in King George Island (Antarctica) and Morro Chico (Chile), were isolated and then used to establish clonal cultures. To understand the phylogenetic relationships and species diversity of Antarctic Asterochloris species, molecular and morphological data were analyzed by using three microscopy techniques (light, confocal laser and transmission electron) and a multi-locus phylogeny with data from the nuclear-encoded internal transcribed spacer (ITS) rDNA and the actin and plastid-encoded ribulose bisphosphate carboxylase large chain (rbcL) coding genes. Morphological data of three Antarctic strains showed significant species-specific features in chloroplast while molecular data segregated the taxa into distinct three clades as well. Each species had unique molecular signatures that could be found in secondary structures of the ITS1 and ITS2. The species diversity of Antarctic Asterochloris was represented by six taxa, namely, A. glomerata, A. italiana, A. sejongensis, and three new species (A. antarctica, A. pseudoirregularis, A. stereocaulonicola).


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