Abstract Detail

Systematics

Buchheim, Mark [1], Toomey, Matt [1].

Haematococcus in North America.

The green flagellate, Haematococcus, is the target of substantial interest due to the alga's ability to produce the valuable carotenoid, astaxanthin.   The more 15,000 research citations for Haematococcus in the last decade have generally focused on optimizing yield and commercialization of astaxanthin.   Largely unnoticed was a handful of publications that have reshaped the taxonomic and phylogenetic breadth of the genus.   As a consequence of this work, all but one of the original Haematococcus species were transferred to the genus Balticola.   The remaining taxon, H. lacustris, has since been shown to harbor cryptic diversity that led to the description of two new species-H. rubens and H. rubicundus-largely on the basis of molecular evidence.   New Haematococcus isolates from North America have been characterized and affirm that H. lacustris is the most commonly encountered species.   Moreover, H. lacustris appears to be globally distributed.   In addition, new strains of H. rubicundus have been isolated from Missouri, Oklahoma and Wisconsin.   Collecting efforts in the Americas have failed to find H. rubens which has only been isolated from Europe.   The new molecular evidence indicates that an additional, species-level lineage exclusively from North America likely exists.   Data from the 18S and 26S rRNA genes, from the internal transcribed spacers (ITS-1 and ITS-2) and from the 5.8S rRNA gene robustly support monophyly of several isolates of Haematococcus that were collected in Oklahoma and Wisconsin.   With this latest finding, the molecular evidence now points to the existence of at least four species-level lineages.   Although Haematococcus has been found on all continents (with the possible exception of Antarctica), the sampling is heavily biased to Europe and the Americas.   Thus, it seems likely that additional sampling on a more global scale will reveal even more diversity.   In addition to advancing our understanding of diversity in this opportunistic and ephemeral green alga, these and subsequent results will help researchers focused on an applied science approach to frame their investigations of Haematococcus in an evolutionary context.

1 - The University of Tulsa, Department of Biological Science, 800 South Tucker Dr., Tulsa, OK, 74104-9700, United States

Keywords:
Haematococcus
Astaxanthin
phylogeny
rDNA.

Presentation Type: Oral Paper
Session: SYSTIII, Systematics III: Algae to Lilioid Monocots
Location: Virtual/Virtual
Date: Tuesday, July 20th, 2021
Time: 3:30 PM(EDT)
Number: SYSTIII003
Abstract ID:999
Candidate for Awards:None