长期取食染镉小麦后中华稻蝗体内镉的累积分布

重金属镉在动物体内的代谢过程主要通过消化途径实现。以食物染毒的方法，采用不同浓度镉溶液培养的麦苗饲喂中华稻蝗（从一龄若虫至成虫），将中华稻蝗成虫不同组织部位（头、翅、足、卵巢／精巢、体壁、前肠、中肠、后肠）解剖，并通过原子吸收分光光度计测定其镉的浓度，统计分析各组织部位镉的累积分布规律。火焰原子吸收测定结果表明，生长于浓度为0、36．67、73．34、110．01、146．68μg·g^-1镉溶液中的小麦，其叶片中镉的累积浓度分别达到1．99、102．88、159．92、255．48、372．68μg·g^-1,与培养液中镉浓度呈显著正相关（Y=2．4379X-0．206，R^2=0．988P〈0．01；Y为小麦中镉浓度，X为镉溶液浓度）；随着镉处理浓度的增加，中华稻蝗头、翅、足、卵巢、体壁、前肠、中肠、后肠中镉的累积浓度基本都呈增加的趋势，例如，在各组织部位中镉累积浓度最高的为中肠，4个处理浓度中雌虫分别为对照组的139．29、82．11、197．94、212．74倍，雄虫为对照组的99．89、70．32、100．17、91．23倍；在各组织部位中镉累积浓度较低的足，雌、雄虫也分别达到了对照组的4．95、8．80、16．23、16．90倍和7．14、12．22、20．59、27．98倍。对中华稻蝗成虫各组织部位镉累积浓度进行比较发现，消化道各部位的累积浓度较其他部位为高，其中，中肠内镉的累积浓度均为最高，前后肠间的累积浓度次之；此外，镉在中华稻蝗头部也有明显的累积，其次是体壁和翅，而卵巢／精巢和足的累积浓度最低。研究结果表明长期取食染毒小麦可导致镉在中华稻蝗体内的累积，且镉在不同组织部位中的累积分布存在差异。

Accumulation and Distribution of Cadmium in Oxya chinensis after Feeding on Wheat Seedlings Contaminated with Cd

Cadmium （Cd） is one of the harmful heavy metals, and is accumulated in animals usually through digestion pathway in ecosystem. In this study, Oxya chinensis, from the first-instar nymphs to the adults, was fed on wheat seedlings cultured in Cd solutions of different con- centrations （0, 36.67, 73.34, 110.01,146.68 μg·g^-1）, the accumulation and anatomical distribution （head, wings, legs, ovary/spermary, body wall, foregut, midgut, hindgut） of Cd in the adults of Oxya chinensis were further analyzed. The accumulated Cd concentrations of wheat seedlings leaves were： 1.99, 102.88, 159.92, 255.48, and 372.68 μg·g^-1when cultured in the Cd solutions of different concentrations 0, 36.67, 73.34, 110.01, 146.68 μg·g^-1, there was a positive correlation between the Cd concentrations in wheat seedlings leaves and the Cd culture solutions （ Y=2.437 9X-0.206, R^2=0.988 P〈0.01; Y： Concentration of Cd in wheat seedlings, X： Concentration of Cd in culture solution）. Moreover, the accumulated Cd concentrations in different parts of Oxya chinensis were increased when fed on wheat seedlings cultured in Cd solutions of different concentrations as above. Cd concentrations of midgut were 139.29, 82.11,197.94, 212.74 times for females and 99.89, 70.32, 100.17, 91.23 times for males compared with those in controls; Cd concentrations of the legs of Oxya chinensis were 4.95, 8.80, 16.23, 16.90 fold in females and 7.14, 12.22, 20.59, 27.95 fold in males compared with those in controls. The results indicated that accumulation of Cd in the midgut was the highest, which was a significant difference compared to that of other parts. Cd was apparently accumulated in the head, followed by the body wall and wings, while the Cd concentration of ovary/spermary and legs were the lowest. The results showed that Cd can be accumulated in Oxya chinensis through the plant, and there were some differences among the different anatomical parts.