不同质量浓度黄莒蒲和狭叶香蒲对铜绿微囊藻的化感作用

分别采用黄菖蒲（IrispseudacorusL．）、狭叶香蒲（TyphaangustifoliaL．）和铜绿微囊藻（Microcystisaeruginosa）共生培养的实验方法研究了不同质量浓度黄菖蒲、狭叶香蒲对铜绿微囊藻的化感作用。结果表明，黄菖蒲在质量浓度大于10g／L时对初始密度为1．0×10^7ind／mL的铜绿微囊藻具有较好的抑制作用，表现为黄菖蒲质量浓度为10、20和40g／L时，第15天对铜绿微囊藻的抑制率分别为30．1％、51．8％和84．0％；狭叶香蒲在质量浓度大于20g／L时对铜绿微囊藻有明显的抑制作用，表现为狭叶香蒲质量浓度为20g／L和40g／L时，第15天对铜绿微囊藻的抑制率分别为34．2％和77．7％，实验过程中，铜绿微囊藻叶绿素a含量逐渐减少，而藻密度、SOD活性及MDA含量先增加后逐渐降低，表明经过一段时间持续地化感胁迫，黄菖蒲和狭叶香蒲可以诱导铜绿微囊藻产生氧化胁迫，导致细胞结构严重损伤和叶绿素大量分解，从而强烈抑制铜绿微囊藻的生长。

Allelopathic effect of different concentrations of Iris pseudacorus L. and Typha angustifolia L. on Microcystis aeruginosa

The study is to investigate the allelopathic effect of different concentrations of L pseudacorus L. and T. a,tgustifolia L. on the inhibition rate （IR）of Microcystis aeruginosa＇s growth through co-cultivated meth- od with Iris pseudacorus L. and Typha angustifolia L. , separately. The results showed that over 10 g/L co-culti- vated concentration of I. pseudacorus L. exhibited significant inhibition on the growth of M. aeruginosa which in- itial concentration was 1.0 × 10^7 ind/mL. At Day 15 of incubation, the IRs on M. aeruginosa ＇ s growth were 30. 1% ,51.8% and 84. 0% versus 10, 20 and 40 g/L of I. pseudacorus L. ＇ s concentration, respectively. Likewise, T. angustifolia L. showed significant inhibition effect on M. aeruginosa＇ s growth over 20 g/L co-cul- tivated concentration. At Day 15 of incubation, the IRs of M. aeruginosa were 34.2% and 77.7% versus T. angustifolia L. ＇s concentration at 20 and 40 g/L, respectively. During the incubation period, the quantity of M. aeruginosa＇s chlorophyll-a decreased gradually, whereas algae density, SOD activity and MDA content in- creased initially and decreased gradually thereafter. This study demonstrated that I. pseudacorus L. and T. an- gustifolia L. could induce M. aeruginosa ＇ s oxidative stress after a period of sustained allelopathic stress, which could cause serious damage on M. aeruginosa ＇ s cell structures, facilitate chlorophyll degradation and eventually inhibit the growth of M. aeruginosa.