Effect of temperature, irradiance on the growth of the green alga Caulerpa lentillifera (Bryopsidophyceae, Chlorophyta)

In order to study the effect of temperature, irradiance, and salinity on the asexual reproduction of Caulerpa lentillifera, we conducted the indoor culture to study these factor effects on the regeneration of C. lentillifera, together with the measurement of photosynthetic parameters such as chlorophyll content, fluorescence characteristics, and rbcL behavior. It was shown that the maximum specific growth rate (SGR) of the alga was at 27.5 °C and 40 μmol photons m−2 s−1, and warm temperature (25.0–30.0 °C) induced the formation of branches. Both lower and higher temperature reduced chlorophyll content and decreased Fv/Fm value, while high rbcL expressions occurred at 27.5 °C. With the irradiance rise, the chlorophyll content decreased and the higher irradiance (100 μmol photons m−2 s−1) decreases Fv/Fm and increases of NPQ. The higher irradiances (40 and 100 μmol photons m−2 s−1) also reduced rbcL expression. This physio-ecological data will be valuable to explore the possible asexual propagation of this green alga and eventually for future large-scale vegetative reproduction.