School of Life Science, Ludong University, Yantai, 264025, China; Department of Marine Science, Incheon National University, Incheon, 22012, Korea.
Research Institute of Basic Sciences, Incheon National University, Incheon, 22012, Korea.
Harmful Algae. 2023 Mar;123:102402. doi: 10.1016/j.hal.2023.102402. Epub 2023 Feb 9.
The response of seaweeds to environmental stressors can be population-specific, and be related to the regime of their habitats. To explore the growth and physiological responses of Ulva prolifera, two strains of this alga (Korean and Chinese strains) were studied under an interaction of temperature (20 and 25 °C), nutrients (low nutrients: 50 μM of nitrate and 5 μM of phosphate; high nutrients: 500 μM of nitrate and 50 μM of phosphate) and salinity (20, 30 and 40 psu). The lowest growth rates of both strains were observed at 40 psu of salinity, independent of temperature and nutrient levels. At 20 °C and low nutrients condition, the carbon: nitrogen (C: N) ratio and growth rate in the Chinese strain were increased by 31.1% and 21.1% at a salinity of 20 psu in comparison to the salinity of 30 psu, respectively. High nutrients decreased the ratio of C:N in both strains with increasing tissue N content. At the same time, high nutrients also increased soluble protein and pigments contents, as well as photosynthetic and growth rates in both strains at the same salinity levels at 20 °C. Under 20 °C and high nutrients conditions, the growth rates and C:N ratio of both strains were significantly decreased with increasing salinity. The pigment, soluble protein and tissue N showed an inverse trend with the growth rate at all conditions. Moreover, the higher temperature of 25 °C inhibited the growth in both strains regardless of nutrients levels. The temperature of 25 °C enhanced the contents of tissue N and pigments in the Chinese strain only at the low nutrients level. The interaction of high nutrients and 25 °C led to the accumulation of tissue N and pigment contents in both strains under all salinity conditions compared to the 20 °C and high nutrients level. The temperature of 25 °C and high nutrients decreased the growth rate in the Chinese strain at both salinities of 30 and 40 psu more than the 20 °C, and low nutrients level at the same salinity. These results suggest that the Ulva blooms caused by the Chinese strain were more impacted at hypo-salinity levels compared to the Korean strain. Eutrophic or high nutrients level enhanced the salinity tolerance in both strains of U. prolifera. There will be a decline of U. prolifera blooms of the Chinese strain at hyper-salinity levels.
海藻对环境胁迫的反应可能具有种群特异性，并与其栖息地的状态有关。为了探索石莼的生长和生理反应，研究了两种石莼（韩国和中国菌株）在温度（20 和 25°C）、养分（低养分：硝酸盐 50 μM 和磷酸盐 5 μM；高养分：硝酸盐 500 μM 和磷酸盐 50 μM）和盐度（20、30 和 40 psu）的相互作用下的生长和生理反应。在 40 psu 的盐度下，两种菌株的生长率都最低，与温度和养分水平无关。在 20°C 和低养分条件下，与 30 psu 的盐度相比，中国菌株在 20 psu 的盐度下，其碳氮比（C:N）和生长率分别增加了 31.1%和 21.1%。高养分降低了两种菌株的 C:N 比，同时增加了组织 N 含量。与此同时，在 20°C 相同盐度下，高养分也增加了两种菌株的可溶性蛋白和色素含量以及光合作用和生长率。在 20°C 和高养分条件下，随着盐度的增加，两种菌株的生长率和 C:N 比都显著降低。在所有条件下，色素、可溶性蛋白和组织 N 与生长率呈相反趋势。此外，较高的温度 25°C 抑制了两种菌株的生长，而不管养分水平如何。较高的温度 25°C 仅在低养分水平下增加了中国菌株的组织 N 和色素含量。在所有盐度条件下，高养分和 25°C 的相互作用导致两种菌株的组织 N 和色素含量的积累，与 20°C 和高养分水平相比。在 30 和 40 psu 的两种盐度下，25°C 和高养分的温度比 20°C 和低养分水平降低了中国菌株的生长率。这些结果表明，与韩国菌株相比，中国菌株引起的石莼水华在低盐度水平下受到的影响更大。富营养化或高养分水平增强了两种石莼的耐盐性。中国菌株的石莼水华将在高盐度水平下降。
