The different responses of growth and photosynthesis to NH4+ enrichments between Gracilariopsis lemaneiformis and its epiphytic alga Ulva lactuca grown at elevated atmospheric CO2
2019
Ji, Zhiwei | Zou, Dinghui | Gong, Jingyu | Liu, Chunxiang | Ye, Changpeng | Chen, Yuning
We investigated how elevated CO₂ affects the responses of Gracilariopsis lemaneiformis and Ulva lactuca to NH₄⁺ enrichments. All algae were incubated under four nutritional conditions (zero addition, 100, 500, and 2500 μM NH₄⁺), and two CO₂ levels (390 ppm and 1000 ppm). The growth, photosynthesis, and soluble protein contents of both species increased under the eutrophication condition (100 μM NH₄⁺). However, the growth and carotenoid contents of the two species declined when NH₄⁺ concentration increased. Under the super eutrophication condition (2500 μM NH₄⁺), all indexes measured in G. lemaneiformis were suppressed, while the growth and photosynthesis in U. lactuca changed indistinctively, both compared with the control. Moreover, under the super eutrophication condition, elevated CO₂ reduced the suppression in the growth of G. lemaneiformis, but decreased the growth of U. lactuca. Nonetheless, G. lemaneiformis displayed much lower growth rates than U. lactuca under the super eutrophication and elevated CO₂ condition.
显示更多 [+] 显示较少 [-]