Bibliographic Detail
Skaloud, P. & Peksa, O., 2010
Reference:
Skaloud, P. & Peksa, O. (2010). Evolutionary inferences based on ITS rDNA and actin sequences reveal extensive diversity of the common lichen alga Asterochloris (Trebouxiophyceae, Chlorophyta). Molecular Phylogenetics and Evolution 54: 36-46.
Abstract:
The genus Asterochloris is one of the most common lichen photobionts. We present a molecular investigation
of 41 cultured strains, for which nuclear-encoded ITS rDNA and partial actin I sequences were
determined. The loci studied revealed considerable differences in their evolutionary dynamics as well
as sequence variation. As compared to ITS data, the actin sequences show much greater variation, and
the phylogenies yield strong resolution and support of many internal branches. The partitioning of ITS
dataset into several regions yielded better node resolution. We recognized 16 well-supported monophyletic
lineages, of which one represents the type species of the genus (Asterochloris phycobiontica), and six
correspond to species previously classified to the genus Trebouxia (T. erici, T. excentrica, T. glomerata, T.
irregularis, T. italiana and T. magna). Only 15% of isolated photobionts considered in our study could be
assigned with certainty to previously described species, emphasizing amazing cryptic variability in Asterochloris.
Concurrently with the formal delimitation of the genus Asterochloris, we propose new combinations
for the former Trebouxia species; furthermore, T. pyriformis is reduced to a synonym of A. glomerata.
The present knowledge of global diversity of Asterochloris algae is discussed.
