Relationship between strains of Coolia monotis (Dinophyceae) from the Atlantic Iberian Peninsula and their sampling sites

- Comparison of cultured strains from three different localities
- Study of growth rates under different light intensities
- Compare different methods of achieving growth rate
- Study of photosynthetic parameters of microalgae under High light stress
- Relate strains locality to their photophysiological preferences

Strains of Coolia monotis from three locations (north, center and south) of the Atlantic Iberian Peninsula were studied to undercover possible geographic preferences in their photophysiology. Growth rates and photosynthetic parameters such as Fv/Fm, α, Ek and rETRmax were analyzed with a Coulter counter, a Water-PAM and a FRRF. The photosynthetic properties were investigated in experiments using strains acclimated to Low Light (LL) and High Light (HL) during the course of a day. The same strains were also used for a HL stress experiment. The highest growth rate (0.29 d− 1) corresponded to Galé strain, from the south of the Peninsula, under 200 μmol photons m− 2 s− 1, suggesting that it was adapted to higher irradiances than the other 2 strains. The rapid light curves taken during the course of a day showed no differences between the strains, but the ones acclimated to LL had higher rETRmax and α, and lower Ek values than the ones acclimated to HL. The HL stress exposure induced photodamage to all strains and the recovery period was not sufficiently long for full recovery of Fv/Fm. Results demonstrated that strains responded differently to treatments, even though were genetically identical at the 28S/ITS-levels. These differences could be related to their original location.