在模拟条件下,通过深入研究光照强度对隐藻生长率的影响,以及不同光照强度下藻细胞对Fe和P的吸收差异,提出了光照强度控制藻细胞对营养元素的吸收,最终限制赤潮藻爆发性增殖的作用途径。研究表明,藻细胞的生长率与光照强度之间呈指数相关关系;隐藻生长的光饱和值与光半饱和值分别为150μmol/(m^2·s)和47μmol/(m^2·s);在低光照强度下藻细胞的生长率较低,但是藻细胞却需要吸收更多的Fe和P,以及Zn、Mn、Co和Mo等微量元素,在光照强度为10μmol/(m^2·s)时,藻细胞生长率仅为光照强度150μmol/(m^2·s)时的十分之一,而藻细胞对Fe和P的吸收量分别提高了1.5倍和1倍。这些研究结果为揭示导致赤潮常在光照良好天气后发生的根本原因提供了全新的认识。
The effects of irradiance on the growth of some harmful algae and the difference in absorption of iron and phosphorus by algae under various light intensities were researched through laboratory culture. The mechanisms of irradiance regulating nutrient uptake as well as the occurrence of harmful algal bloom are discussed. The results show that there is an exponential correlation between algal growth rate and irradiance. The light saturation and semi-light saturation for the growth of Cryptomonas sp. are 150 μmol/(m^2 · s) and 47 μmol/(m^2· s), respectively. More uptake of Fe, P and other trace elements such as Zn, Mn, Co and Mo is observed under low irradiance, although the algal growth rate is slow. The growth rate at 10 μmol/(m^2· s) is only 10% of that at 150 μmol/(m^2 · s), whereas Fe and P uptake increases by 1.5 and 1 times, respectively. These results provide new knowledge for understanding the main reason why red tides often occur with sufficient irradiance.