摘要

The diversity and heavy metal (HM) tolerance of endophytic fungi (EF) associated with Dysphania ambrosioides, a hyperaccumulator from two Pb-Zn contaminated sites were investigated. A total of 237 culturable EF were isolated and identified to 43 taxa based on morphological characteristics and rDNA internal transcribed spacer analysis, of which 13 occurred as endophytes of both sites, while other taxa were only found in either site. The colonization rate, dominant genera, community structure of EF as well as the HM content in the plant from two sites were significantly different. We suggest that these differences may result from the difference in the soil HM content: lower HM content in the soil, more EF in the plant, which may enhance the plant HM accumulation and thus result higher HM in it. HM tolerance tests indicated that 50% of the isolates exhibited HM tolerance. Among them, two isolates exhibited better HM tolerance, of which FT2G59 could tolerate Pb, Zn, and Cd, and the minimum inhibitory concentration (MIC) of them were 30-50, > 680, 20-30 mmol/l, respectively. While, the isolate FT2G7 could tolerate Cd, and the MIC was 30-50 mmol/l. These isolates may have potential application in phytoremediation.