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.
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. Only 15% of isolated photobionts considered in our study could be assigned with certainty to previously described species, emphasizing amazing cryptic variability in Asterochloris.
New combinations for the former Trebouxia species are proposed.