The Hormesis Effect Of Glyphosate On Six Kinds Of Marine Algae

Hormesis is a dose-response relationship that is characterized by a low dose stimulation and a high dose inhibition. The dose response relationship may be graphed to illustrate an inverted-U shaped dose response or a J-shaped dose-response depending on the endpoint being assessed. This theory is different from the traditional threshold model in toxicological. Its most distinct character is biphasic dose-response which is observed as being a low dose stimulation while inhabitation at higher dose. In the recent decades, there has been more and more scholars in toxicology develop the research of hormesis abroad. They got a great deal of experimental data, and approved that many substances (including toxical chemicals, radiations and so on) had hormesis on the organisms. These make the biphasic does-response theory approbated in the toxicology gradually.This paper was composed based on the research status in and abroad. We chose the herbicide glyphosate as the chemical, studied the stimulation effect of six kinds of marine algae(Chaetoceros curvisetus, Platymonas subcordiforus, Dunallelia salina, Isochiysis galbana 3011, Chlorella pynnoidosa, Platymonas helgolandica). We got many parameters, such as none detected effect concentration (NDEC), the highest stimulate intension, the relative growth rate (RGR), using the model calculation. And the main research productions are as follows:According to the operation time, operation dose and operation intensity, we can set off the experiment algae into three kinds: 1. sensitive type, which has low NDEC, acted stimulation effect at lower dose, got max intensity over 160%, and remarkably restrained when the dose was over 20 mg-L-1. The representative species was Chaetoceros curvisetus.2. Secondary sensitive type, which had its representative specieses as Dunallelia salina, Chlorella pynnoidosa, Platymonas helgolandica, got NDEC between 20 mg-L-1-30 mg-L-1, the max intensity between 130%-140%, and remarkably restrained when the dose was over 50 mg·L-1.3. Insensitive type. The NDEC was over 50 mg-L-1, the max intensity was less than 130%. The algae can steal grow well as the dose was over 100 mg·L-1. The representative specieses were Platymonas subcordiforus, and Isochrysis galbana 3011.The glyphosate had biggish influence on the Chaetoceros curvisetus, Platymonas subcordiforus, Dunallelia salina, Platymonas helgolandica cell growth, had little influence on the Isochrysis galbana 3011, Chlorella pynnoidosa, however. There is no significant difference between stimulation group and blank group. According to the experiment result and data correlation anylisis, the the stimulatoin effect mechanism of glyphosate on these algae might be the overconprehension.