PT  - JOURNAL ARTICLE
AU  - Bock, Christina
AU  - Medinger, Ralph
AU  - Jost, Steffen
AU  - Psenner, Roland
AU  - Boenigk, Jens
TI  - Seasonal variation of planktonic chrysophytes with special focus on Dinobryon.
DP  - 2014 Sep 1
TA  - Fottea
PG  - 179--190
VI  - 14
IP  - 2
AID - 10.5507/fot.2014.014
IS  - 18025439
AB  - The diversity of chrysophytes is often underestimated in morphological surveys because of the limited amount of detectable characters under the light microscope. Addressing biodiversity issues solely based on morphological characters is further problematic since molecular analyses revealed a huge genetic diversity within morphotypes, even showing polyphyly in some morphological defined species. In order to address the seasonal variations of chrysophytes, 10 samples were collected in 2007 from the oligotrophic lake Fuschlsee (Salzkammergut, Austria). By using Dinobryon as a case study, we compared different gene phylogenies of single cells of the 18S, ITS (including ITS1, 5.8S, partial ITS2) and the mitochondrial marker COI. No clear molecular phylogenetic separation between morphological identified cells of D. divergens and D. bavaricum could be accomplished based on the 18S rDNA sequences. ITS and COI sequence data revealed a higher genetic diversity then the 18S, with several independent lineages consisting of D. divergens cells. We further encountered divergent phylogenies by comparing 18S/ITS sequence data with COI data within D. pediforme, D. sociale and D. bavaricum lineages. By combining the results of the single cell approach with seasonal data based on 454 pyrosequencing, we addressed the question in how far one morphological species may dominate in the water column over the course of a single year. The results of the 454 pyrosequencing revealed that the D.divergens/D. bavaricum lineage shows the highest abundance from all Chrysophyceae/Synurophyceae and strong seasonal variations with peaks in May and October.