无机氮浓度及其配比对细基江蓠繁枝变型生长及生化组成的影响

Effects of different inorganic nitrogen sources and concentrations on the growth and biochemical constituents of Gracilaria tenuistipitata var. liui Zhang et Xia

在实验室条件下分别研究了NO3--N和NH4+-N浓度及其配比对细基江蓠繁枝变型(Gracilariatenuistipitatavar.liuiZhangetXia)生长及生化组成的影响。结果表明,过低的NO3--N浓度(0,10μmol/L)或过高的NO3--N浓度(60,80μmol/L)、过低的NH4+-N浓度(0,2.5μmol/L)或过高的NH4+-N浓度(10,20,40μmol/L)、过低的NH4+-N/NO3--N比值(1/35,1/7)或过高的NH4+-N/NO3--N比值(3/7,4/7)条件下,江蓠均表现为生长速率明显减慢(P<0.05)、藻体内藻红素(PE)、叶绿素a、蛋白质含量显著降低(P<0.05);而分别在NO3--N20μmol/L、NH4+-N5μmol/L、NH4+-N/NO3--N2/7(TIN20mol/L)的条件下,江蓠可获得最快生长速率和最高的PE、叶绿素a、蛋白质含量以及最低的碳水化合物/蛋白质比值。

In order to investigate the effects of different inorganic nitrogen sources and concentrations on the growth and the biochemical constituents in macroalgae, Gracilaria tenuistipitata var. liui Zhang et Xia was cultured with varied nitrogen sources（NO3^--N, NH4^＋-N and NH4^＋-N/NO3^--N）and at different concentrations in laboratory. The results showed that Gracilaria growth was inhibited considerably（P〈0.05） and the contents of PE, Chl-a and protein were respectively lower than those of control（P〈0.05） when NO3^--N concentrations were 0, 10, 60 and 80μmol/L, or when NH4＋-N concentrations were 0, 2.5, 10, 20 and 40μmol/L, or when levels of NH4＋-N/NO3^--N were 1/35, 1/7, 3/7 and 4/7. At suitable nitrogen environment （NO3-N20μmol/L, NH4^＋-N5μmol/L, NH4^＋-N/ NO3^--N 2/7 and TIN20mol/L）, the Gracilaria showed the best growth and the highest levels of of PE, Chl-a and protein and the lowest value of carbohydrate/protein ratio compared with other groups（P〈0.05）, respectively.