摘要:
通过野外采集漳泽水库不同采样点的黑斑蛙蝌蚪,采用微核、核异常、彗星试验3种方法,研究了水体污染对蝌蚪红细胞微核率、核异常率和DNA断裂3种遗传毒性指标的影响。微核试验结果显示:各采样点红细胞微核率除泽头采样点外,均明显高于阴性对照(P < 0.01),其中水库入口店上采样点的微核率最高,为6.87‰,位于水库上、中、下游3个采样点的微核率逐渐下降,从大到小依次为:下韩(5.45‰)、台上(3.71‰)、泽头(2.33‰)。核异常试验结果显示:各采样点核异常率均明显高于阴性对照(P < 0.01),核异常率与微核率二者变化趋势趋于一致。彗星试验结果显示:各采样点红细胞尾长、尾矩与阴性对照相比差异均极显著(P < 0.01),尾长、尾矩的变化趋势与微核试验结果一致。对同样位于水库中游的采样点司徒和台上的4个指标进行多重比较分析发现:微核率、核异常率和彗星尾长差异均不显著(P > 0.05),而尾矩差异显著(P < 0.05)。综上可知,漳泽水库各采样点水体具有较高的遗传毒性,主要毒性作用为引起染色体(DNA)断裂;各采样点遗传毒性指标变化规律与水体污染物变化规律趋于一致,因此应用这3种方法可以有效地对水体遗传毒性进行检测。
Abstract:
Micronucleus test, nucleus abnormality test and comet test were applied to explore the effects of the water pollutant on three genetic toxicity indexes, namely, micronucleus frequency, nuclear anomalies frequency, DNA fracture of Rana nigromaculata sampled from five sampling points of Zhangze Reservoir. The results of micronucleus test showed that the erythrocyte micronucleus frequency of all sampling points was significantly higher than that of the negative control (P < 0.01), except for that of Zetou. The highest micronucleus frequency was 6.87‰ at Dianshang located in the entrance of the reservoir, and the micronucleus frequency decreased gradually at three sampling points located in the upstream, midstream and downstream, i. e., Xiahan (5.45‰), Taishang (3.71‰) and Zetou (2.33‰). The results of nucleus abnormality showed that nuclear abnormality frequency of the erythrocytes at all sampling points was significantly higher than that of the negative control (P < 0.01). The change trend of nuclear abnormality of all sampling points was consistent with that of the micronucleus test. The results of comet test showed that both the tail length and the tail moment of the erythrocytes were significantly higher than that of the negative control (P < 0.01) at all sampling points, and the change trend of both the tail length and the tail moment was consistent with that of the micronucleus test. By comparing and analyzing four indexes of Situ and Taishang both located in the midstream, it is found that no significant difference (P > 0.05) was observed in the micronucleus frequency, nuclear abnormality and comet tail length, but there was significant difference (P < 0.05) in the comet tail moment. In conclusion, the water from different sampling points in Zhangze Reservoir showed high genetic toxicity, which mainly caused chromosome (DNA) fracture. The genetic toxicity indexes of all sampling points varied consistently with the pollutant change of the water body, so the genetic toxicity of the water body can be detected effectively through the three methods mentioned above.
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