重金属胁迫下外生菌根真菌Boletus edulis重金属积累分配与生长微环境变化  

Changes of accumulation and distribution of elements and micro-ambient for ectomycorrhizal hypha

作　　者：李婷[1] 黄艺[1] 黄志基[1] 

机构地区：[1]北京大学环境学院,北京100871

出　　处：《生态环境》2005年第6期870-875,共6页Ecology and Environmnet

基　　金：广东自然科学基金资助(035018)

摘　　要：在离体培养条件下,对外生菌根真菌Boletusedulis菌丝铜镉积累分配与生长微环境变化进行研究。结果表明,铜镉胁迫下菌落直径具有相似的增长模式。与对照相比,低浓度的铜镉处理均促进了菌丝的生长,而高浓度则产生抑制作用。Boletusedulis具有很强的铜镉吸收积累能力,显示出较好的重金属耐受性。菌丝体是重金属在离体培养体系中积累的主要场所,最高处理浓度时,菌丝体内的铜镉浓度分别达到对照的26.6和28倍,而菌丝分泌物的作用相对较小。菌丝体对生物体必需元素铜和非必需元素镉具有不同的积累模式,并可根据重金属的种类,有效地调节生长微环境,以降低重金属对菌丝体的生物有效性。这可能是外生菌根真菌的一种重金属抗性机理。The experiment was conducted to study heavy metal accumulation, distribution and micro-ambient change of ectomycorrhizal fungi Boletus edulis in vitro. The study found that the growth modles of ectomycorrhizal fungi were similar in both Cu and Cd stressed environment. Compared with control, low concentration treatments of Cu and Cd enhanced the growth of fungi, but high ones prevented it. Boletus edulis in viro had a strong ability to absorb Cu and Cd, and showed higher heavy metal tolerance. Ectomycorrhizal hypha was the main site for heavy metal to accumulate. The concentration of Cu and Cd in the hypha under the highest treatments were 26.6 and 28 times respectively more than control. However, the effect ofhyphal exudates on the resistance to heavy metals was relatively small. The accumulated models of two heavy metals were significantly different. Mycelia might alleviate heavy metal damage by changing cultivation environment selectively. This could be one of resistance mechanisms ofhypha to heavy metals.

关 键 词：外生菌根真菌 铜 镉 微环境 

分 类 号：X53[环境科学与工程—环境工程] X17