促植物生长内生细菌强化植物修复锌污染土壤

摘要

以超积累植物东南景天为材料，采用盆栽试验探讨了接种内生菌VI8L2、II8L4和VI8R2对土壤Zn有效性、植物生长和吸收积累锌的影响。结果表明，接种内生菌VI8L2、II8L4和VI8R2能够促进东南景天在Zn污染土壤中的生长，其根系和地上部的生物量分别比对照增加了80%~525%和11%~47%。在人工ZnCO3污染土壤中，接种菌株VI8L2、II8L4和VI8R2显著增加了东南景天根系和地上部的Zn含量；在人工Zn3(PO4)2污染土壤中，菌株VI8L2使东南景天地上部和根系的Zn含量分别比对照增加了44%和39%，但是菌株Ⅳ8R2显著降低了东南景天地上部的Zn含量；在长期被酸性废水污染水稻土壤中，接种菌株VI8L2、II8L4和VI8R2显著增加了东南景天根系的Zn含量，但降低了地上部的Zn含量。这表明金属抗性促生细菌可用于强化植物修复重金属污染土壤。%Three bacterial endophytes of Sedum alfredii, VI8L2, II8L4 and VI8R2, were examined for promoting soil Zn bioavailability and Zn accumulation in S. alfredii. Results showed that three strains were re-introduced into S. alfredii rhizosphere soils under Zn stress and resulted in better plant growth, as roots biomass increased from 80% to 525% and shoot biomass from 11% to 47%compared with the uninoculated ones. Strains IV8L2, II8L4 and IV8R2 significantly increased shoot and root Zn concentrations in the ZnCO3 contaminated soil. Inoculation with strain IV8L2 resulted in 44% and 39% higher shoot and root Zn concentrations, while strain IV8R2 significantly decreased shoot Zn concentration in the Zn3(PO4)2 contaminated soils. In the aged contaminated soil, isolates IV8L2, II8L4 and IV8R2 significantly increased root Zn concentration, but decreased shoot Zn concentration of Sedum alfredii. It suggested that endophytes might be used for enhancing phytoextraction efficiency.