不同质量浓度黄菖蒲和狭叶香蒲对铜绿微囊藻的化感作用

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

分别采用黄菖蒲(Iris pseudacorus L.)、狭叶香蒲(Typha angustifolia L.)和铜绿微囊藻(Microcystis aeruginosa)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10 g/L时对初始密度为1.0×107ind/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40 g/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20 g/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20 g/L和40 g/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。

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.