不同植物对高浓度铀胁迫的响应与铀富集植物筛选

Response of Plants to High Concentrations of Uranium Stress and the Screening of Remediation Plants

研究植物对铀的抗性及富集能力对修复铀（u）污染土壤具有重要意义。在每千克土中施用0和500mgu，评价10科14种植物对高浓度U胁迫的响应和U富集能力，筛选修复植物。结果表明：（1）高浓度u胁迫使黄秋葵（Hibiscus esculentus L．）种子出苗减少66．7％，但不影响木耳菜[Gynura cusimbua（D．Don）S．MooreL．]、灰灰菜（Chenopodium albumL．）和四季豆（Phaseolus vulgaris var．humilis Alef）种子出苗；导致芝麻（Sesamum indicum L．）出苗后1个月内全部死亡，柳叶苋（Amaranth）和红圆叶苋（Iresine herbstii‘Aureo-reticulata’）植株成活数减少80％左右，但不影响空心莲子草这[Alternanthera philoxeroides（Mart．）Griseb．]、灰灰菜和四季豆的植株成活。（2）高浓度铀胁迫降低试验植物的生物产量8％～99％，四季豆抗胁迫能力最强，西葫芦（Cucurbita pepo L．）、高粱[Sorghum bicolor （L．）Moench]、蕹菜（Ipomoea aquatica Forsk）、向日葵（Helianthus annuus）、灰灰菜、空心莲子草抗胁迫能力较强。（3）植物在无铀污染土壤中和高浓度铀污染土壤中对铀的吸收能力不同。在无铀污染土壤中，铀含量高的是千日红（Gomphrena globosa）和西葫芦，分别是2．249和1．620mg·kg-1DW；而在高浓度铀污染土壤中铀含量高的是菊苣（Cichorium intybusL．）、柳叶苋和蕹菜，分别是728．7、413．8和337．6mg·kg-1DW。（4）高粱、向日葵和空心莲子草地下器官铀含量高、铀固定量较大，四季豆和蕹菜茎叶铀含量较高、铀提取量较大。因此，对高浓度铀污染土壤，四季豆和蕹菜是良好的提取修复植物，高粱、向日葵和空心莲子草是良好的固持修复植物。

Studies of the resistance and accumulation ability of different plant species to uranium （U） has important influence on the bioremediation of U contaminated soil. The resistance and enrichment ability of high concentrations of U （500mg· kg-1 soil） in fourteen plant species were investigated and evaluated in this study in order to screen remediation plants for governance soil U contamination. The results showed that ： （1） high concentrations of U stress had different effects on the emergence and survival of the different plants. The seed emergence of Hibiscus esculentus was reduced by 2/3, but the seed emergence of Gynura cusimbua （ D. Don） S. Moore, Chenopodium album L. and Phaseolus vulgaris var. humilis Alef were not reduced. Under the contaminated soil, all the sesamum indicum died within a month after the emergence and the survival number of Amaranth and Iresine herbstii ＇ Aureo-reticulata＇ reduced by about 80%. But the survival number of Alternanthera philoxeroides （ Mart. ） Griseb. , Chenopodium album L. and Phaseolus vulgaris var. humilis Alef were not influenced. （2） The biomass of the plants would be reduced by 8 - 99% in the uranium- contaminated soil. The anti-stress ability of Phaseolus vulgaris var. humilis Alef was the strongest in the fourteen plants, and Cucurbita pepo L. , Sorghumbicolor （L.） Moench, Ipomoea aquatica Forsk, Helianthus annuus, Chenopodium album L. and Alternanthera philoxeroides （Mart.） Griseb. showed some the anti-stress ability. （3） Significant differences were found in the capacity of plants to absorb uranium between under high-uranium contaminated soil and under the non-uranium contaminated soil were. The plants with higher uranium content in thenon-contaminated soil were Gomphrena globosa, and Cucurbita pepo L. , which were 2. 249 mg·kg- 1DW and 1. 620mg·kg- 1DW, respectively. But the plants with higher uranium content in the high uranium contaminated soil were Cichorium intybus L. , Amaranth and Ipomoea aquatica Forsk,which were 728.7, 413.8 and 337.6 mg·kg-1DW, respectively. （4） The uranium content of roots and amount fixed by roots per area of Sorghum bicolor （ L. ） Moeneh, Helianthus annuus and Alternanthera philoxeroides （Mart.） Griseb. were bigger, and the uranium contents of stem and leaves and amount extracted by stem and leaves per aera of Phaseolus vulgaris vat. humilis Alef and waterspinach were bigger. Phaseolus vulgaris var. humilis Alef , waterspinach , Sorghum bicolor （L.） Moench, Helianthus annuus , and Alternanthera philoxeroides （Mart.）Griseb. could be taken as repaired plants and Phaseolus vulgaris var. humilis Alef, waterspinach were good ones.