缘管浒苔和羽藻氮、磷营养生理学研究

Nitrogen and phosphorus nutrition physiology of Enteromorpha linza and Bryopsis plumosa(Cholorophyta)

以无性繁殖系为材料,开展了缘管浒苔和羽藻对NO3-,NH4+和PO43-的吸收动力学、生长动力学研究。吸收动力学研究结果表明缘管浒苔和羽藻对NO3-和PO43-的吸收方式为主动运输,对NH4+的吸收方式为被动扩散。缘管浒苔对NO3-的最大吸收速率(Vmax)、对NH4+的吸收斜率都大于羽藻,说明缘管浒苔对高浓度的NO3-和NH4+具有更强的吸收能力。缘管浒苔吸收NO3-和NH4+的a值远大于羽藻,说明在低营养盐浓度时,缘管浒苔对NO3-和NH4+的亲和力更强。在PO43-的吸收中,羽藻的最大吸收速率(Vmax)远大于缘管浒苔,说明羽藻对高浓度PO43-的吸收能力更强,但缘管浒苔的a值远大于羽藻,说明前者在低营养盐浓度时PO43-的亲和力更强。生长动力学研究结果表明,硝酸氮是促进两种海藻快速生长的最适宜氮源形式,氨氮更易促进藻体叶绿素的积累。在相同氮营养条件下,羽藻表现出比缘管浒苔更强的生长优势。

The studies on the uptake and growth kinetics of NO-3,NH＋4和PO3-4N in the clone of Enteromorpha linza and Bryopsis plumosa were conducted.The results suggested that NO-3 and PO3-4 were taken up in the form of active uptake by the two alga,with NH＋4 taken up by passive diffusion.The parameters of Vmax and straight slope for E linza were higher than that for B.plumose,which suggested that E.linza could be more favor to high N than B.plumosa.Moreover,the value of a（Vmax/Ks） for NO-3 and NH＋4 in E.linza was obviously higher than that in B.plumosa,which showed that E.linza could have more approachability to low N than B.plumosa.As for the uptaken of PO3-4,E.linza may have higher P uptake capacities at high P and lower approachability to low P than B.plumosa due to the higher Vmax and lower a than B.plumosa.NO-3 is the most favorite N form to meet the growth for both species,while NH＋4 is more object to increase the accumulation of chlorophyll than NO-3.In addition,B.plumosa exhibited higher growth rate than E.linza under same N condition.