重金属抗性内生真菌与其宿主植物重金属抗性关系初探

The Relationship of Heavy Metal Resistant Endophyte and the Heavy Metal Resistance Ability of Their Host Plants

采用纯培养分离方法分别从重金属富集植物(大叶相思)与非富集植物(水禾、水稻)根内及根际分离到不同种类的真菌菌株。重金属抗性菌株的筛选结果表明,3种植物内生真菌重金属抗性菌株比例高于根际真菌,其中重金属富集植物内生真菌抗性菌株数目高于非富集植物内生真菌,且富集植物重金属抗性内生真菌的比例明显高于根际真菌,但非富集植物重金属抗性内生真菌的比例与根际真菌差别不明显。这些重金属抗性真菌多属于青霉、曲霉、镰刀菌、木霉等与植物有密切关系的种属。这些结果初步表明重金属富集植物内生真菌与其宿主植物富集重金属的能力有密切关系。

In order to explore the role of endophyte in the bioremediation of heavy metals in contaminated soil, the method of pure culture isolation was used to obtain different kinds of fungi strains from the root and rhizosphere of a heavy metal accumulator （A ccacia auriculifomis） and non accumulators （Hygroryza aristata and Oryza sativa）. Screening results of heavy metal resistant strains showed that the proportion of heavy metal resistant strains in endophytic fungi was higher than that in rhizosphere fungi of all the three plants. The number of resistant strains of endophytic fungi in the heavy metal accumulator was larger than that in non accumulators. In the heavy metal accumulators, the proportion of heavy metal resistant strains in endophytic fungi was higher than that in rhizosphere, while, in the non accumulators （Hygroryza aristata and Oryza sativa）, the proporation of heavy metal resistant endophytic fungi and those in rhizosphere fungi had no obvious difference. The heavy metal resistant fungi in the plants mainly belong to the species closely related to plants, such as Penicillium sp., Aspergillus sp., Fusarium sp. and Trichoderma sp., et al. These results indicated a close relationship between heavy metal resistant endophytic fungi in heavy metal accumulators and the accumulation ability for heavy metals of their host plants.