红树植物木榄有机溶剂提取物对球形棕囊藻的抑制效应

基于化感作用原理,利用有机溶剂对红树植物木榄(Bruguiera gymnorrhiza)叶片中的活性物质进行连续提取分离,分别得到正己烷相、乙酸乙酯相、正丁醇相和水相提取物。利用这些提取物进行抑藻实验,通过测定球形棕囊藻(Phaeocystis globosa)的细胞密度发现:四种组分提取物对球形棕囊藻均具有显著的化感抑制作用;正己烷相和乙酸乙酯相提取物对球形棕囊藻的抑制效果明显优于正丁醇相和水相提取物的抑制效果。正己烷相提取物和乙酸乙酯相提取物对球形棕囊藻的48h EC50分别为14.90 mg/L和12.18 mg/L。研究表明,藻细胞初始接种密度影响提取物的抑藻效应,低接种密度时抑制率极高,而随着接种密度的升高抑制率下降;接种密度极高时,提取物不但不会抑制甚至还会促进藻细胞的生长。

Inhibitive effects of organic solvent extracts from mangrove plant Bruguiera gymnorrhiza on Phaeocystis globosa

Based on allelopathic principles,we used organic solvents to extract the active substances from mangrove plant Bruguiera gymnorrhiza,and extracts of hexane phase,ethyl acetate phase,n-butyl alcohol phase and water phase were obtained respectively.The experiment was carried out to test the inhibitive effects of these extracts on algae.Measuring the cell density of Phaeocystis globosa,we found that all of the extracts had significantly inhibitive effects on P.globosa,and the inhibitive effects of extracts of hexane phase and ethyl acetate phase were better than those of n-butyl alcohol phase and water phase.The 48h-EC50 of extracts of hexane phase and ethyl acetate phase on P.globosa were 14.90 mg/L and 12.18 mg/L,respectively.The initial algal density(IAD) was considered an important factor to influence the inhibitive effects of extracts.The inhibitive rate(IR) was high at low IAD,while it decreased with the increasing of IAD.At a higher IAD,the extracts promoted the growth of P.globosa,rather than inhibited the growth.