不同氮、磷浓度及配比对鼠尾藻幼苗生长的影响

摘要

Seedlings of sea weed Sargassum thunbergii was cultivated in nutrient medium containing different concentrations of nitrogen (N) (0 ,2 ,4 ,6 ,8 ,and 10 mg/L ) and phosphorus (P) (0 ,0 .2 ,0 .4 , 0 .6 ,0 .8 ,and 1 .0 mg/L) to evaluate the effect of N and P concentrations on the sea weed growth and development .After that ,a two-factor trail was conducted to investigate the ratio of N to P (5∶1 ,10∶1 , 15∶ 1 ,20 ∶ 1 ,25 ∶ 1 ,30 ∶ 1 ,35 ∶ 1 ,and 40 ∶ 1) on the sea weed growth and development at P concentration of 0 .4 mg/L for 7days .The results showed that the concentrations and proportion of N and P in the medium had great significant influence on the grow th of the seedlings (p <0 .01) ,with interaction between N and P (p <0 .05) .The specific growth rate of the seedlings was found to be increased with the increase in N concentration ,with the maximal specific grow th rate at 0 .40 mg/L ,and at a ratio of N to P=20∶1 .The findings suggest that a good growth of S .thunbergii seedlings be achieved at suitable nutrient concentration and ratio of N and P in the medium .%采用鼠尾藻幼苗，对其在不同氮、磷质量质量浓度的人工培养基中进行培养，研究不同氮、磷质量浓度及氮、磷比的差异对鼠尾藻生长发育的影响。单因素试验中，氮的质量浓度分别为0、2、4、6、8、10mg／L，磷的质量浓度分别为0、0．2、0．4、0．6、0．8、1．0mg／L，之后进行双因子试验。氮、磷比试验中两者质量浓度比分别为5∶1、10∶1、15∶1、20∶1、25∶1、30∶1、35∶1、40∶1，其中磷质量浓度为0．4 mg／L。试验时间为7 d。试验结果表明，氮和磷对鼠尾藻幼苗的生长影响极显著（P＜0．01），且交互作用影响显著（P＜0．05）。随着氮质量浓度的升高，鼠尾藻幼苗的特定生长率呈上升趋势；在磷质量浓度为0．40 m g／L时，鼠尾藻幼苗特定生长率最高。不同氮、磷质量浓度比对鼠尾藻幼苗特定生长率的影响极显著（ P＜0．01），在氮、磷质量浓度比为20∶1时，鼠尾藻幼苗特定生长率最高。本研究结果表明，在鼠尾藻幼苗的培育过程中，对培育环境的营养物质进行有目的性的调控，设置适宜的营养盐浓度及配比，可以实现较高的生长速率。