温度和盐度对几种大型海藻生长率和NH_4-N吸收的影响

Effects of temperature and salinity on growth of G. tenuisti pitata var. liui, U. pertusa, G. filicina and NH_4-N uptake of G.tenuistipitata var. liui

温度和盐度对细基江蓠繁枝变型 (Gracilariatenuistipitatavar.liui)、孔石莼(Ulvapertusa)和蜈蚣藻 (Grateloupiafilicina)生长率及细基江蓠繁枝变型NH4-N吸收的影响进行了实验研究 .结果表明 ,温度和盐度对上述 3种海藻生长率及NH4-N吸收均有显著影响 .3种海藻的生长适宜温度和盐度范围分别为细基江蓠繁枝变型 2 0～ 30℃ ,1 5～ 30 ,孔石莼 1 5～ 2 5℃ ,1 5～ 40 ,蜈蚣藻 2 0～ 2 5℃ ,2 5～ 35 ;最大日特定生长率 (SGR)分别为 8 6 6 % ,1 2 2 8% ,2 2 4% ;N饥饿细基江蓠繁枝变型对NH4-N的吸收存在短期的快吸收 .细基江蓠繁枝变型NH4-N吸收的最适温度和盐度范围分别为 1 5～ 2 5℃ ,1 0～ 2 5 .生长率及NH4-N吸收速率与温度和盐度之间分别存在以下关系 :SGRG .t.=0 873(S - 5 487) (T - 9 0 0 7)e(-0 0 70 8S -0 0 745T) ;SGRU .p .=0 2 2 2 (S - 2 6 6 5 )e-0 0 47S(T - 9 98)e-0 0 0 0 5 7(T -9 98) 2 7;SGRG .f.=2 6×1 0 -4 (S - 1 0 85 6 ) (T - 1 1 70 4)e0 15 6T -3 36× 10 -6STe0 2 19T;Vupt=1 1 81 2 (S - 4 0 81 )(T - 9 2 2 1 )e-0 1S -0 14 8T.

The effect of temperature, salinity on the growth of G. tenuistipitata var. liui, U.pertusa , G. filicina and NH 4-N uptake by nitrogen starved G. tenuistipitata var. liui is studied indoor. The results show that the maximal specific growth rate per day may reach as high as 8.66%, 12.28%, 2.24 % at favorable temperature of 20～30 ℃, 15～25 ℃, 20～25 ℃ and salinity of 15～30,15～40,25～35 respectively. The addition of NaHCO 3 (2.5 mmol/dm 3) stimulated growth, suggesting an inorganic carbon limitation in static cultures. Nearly all NH 4-N in the medium (60 μmol) are assimilated within 24 h at the combinations of 15 ℃, 20 ℃,10 and 20, the uptake is slower at lower temperature (10 ℃) and higher salinity (40). The correlation models indicat that temperature and salinity are the major factors affecting growth and ammonium uptake.