Experimental study on effects of hexavalent chromium on crop seed germination under solution culture

In order to ensure the safe utilization of the reclaimed water for irrigation, some experiments on studying the influence of Cr(Ⅵ) on the seed germination of 4 kinds of typical crop seeds have been done. The results show that there is no significant difference in germination index among treatments at the low concentration (＜1 mg/L) of Cr(Ⅵ). With the increase of the concentration of Cr(Ⅵ), the seed germination of the crop is significantly inhibited. The higher the concentration of Cr(Ⅵ) is, the stronger the inhibition is. In addition, the effect of Cr(Ⅵ) on the growth of crop sprouts and roots of the crop is stronger than that on the seed germination of the crop. There is strongly positive relationship between the concentration of Cr(Ⅵ) and the inhibition rate of crop sprout, root growth and fresh weight. The effect of inhibition on root growth is stronger than that on sprout. By computing and comparing EC25, the sensitivities to Cr(Ⅵ) of 4 typical crops is: tomato>wheat>cucumber>maize.