凤眼莲根系分泌物对塔玛亚历山大藻的化感作用

以塔玛亚历山大藻香港株(Alexandriumtamarense,HKstrain)为材料,研究了凤眼莲(Eichhorniacrassipes)根系分泌物及其丙酮、乙酸乙酯提取物对塔玛亚历山大藻的化感作用(Allelopathic effect)。凤眼莲根粉末的用量为0.1g/L、0.5g/L、1.0g/L、1.5g/L和2.0g/L;丙酮、乙酸乙酯提取物的用量为0.01g/L、0.03g/L、0.05g/L和0.07g/L。由于凤眼莲根系丙酮、乙酸乙酯提取物水溶性比较低,实验中,溶剂提取物置于盖玻片上。培养体系中溶剂提取物的实际浓度通过实验前后盖玻片的差值获得。实验结果表明,凤眼莲根粉末用量大于1.5g/L,对塔玛亚历山大藻抑制率100%,0.5g/L和1.0g/L4d后开始有促进生长的作用。凤眼莲根系丙酮、乙酸乙酯提取物的实际浓度达到0.038g/L、0.022g/L时,对塔玛亚历山大藻抑制超过50%。凤眼莲作为杀藻剂的材料有一定的应用前景。

ALLELOPATHIC EFFECTS OF EICHHORNIA CRASSIPES ROOTS ON ALEXANDRIUM TAMARENSE

Allelopathic effects of dry powder and extract of acetone/ethyl acetate of Eichhornia crassipes roots on Alexandrium tamarense(HK strain)were evaluated 0.1 g,0.5g,1.0g,1.5g and 2.0g/L of E.crassipes root powder were added,respectively.Due to low solubility of extracts,a control of slide was used as carrier to measure the actual concentration of extracts in the cultures.At first,0.01g,0.03g,0.05g,0.07g/L of extracts were put into the weighted slides.Then the slides were added to the flasks containing 100mL of A.tamarense.At the end of the experiment,the slides were taken out,dried and weighted.The actual concentration of extracts in the cultures was obtained from the loss in weight.The results showed that the growth of A.tamarense was absolutely inhibited when the algae was exposured to dry powder of E.crassipes roots at above 1.5g/L.When the concentration of dry powder of E.crassipes roots were 0.5g/L and 1.0g/L,the growth of algae increased after 3 days.The growth of A.tamarense was also inhibited at the actual concentration of 0.038g/L and 0.022g/L extract of acetone and ethyl acetate of E.crassipes roots,respectively.It suggested that E crassipes could be a potential algaecide to control harmful algal blooms.