In vitro saprotrophic basidiomycetes tolerance to pendimethalin

Pendimethalin is a dinitroaniline herbicide classified among the persistent-bioaccumulative toxics. In this paper, the tolerance to this herbicide has been studied in isolates of basidiomycetes (10 species including 9 wood-rotting and 1 litter fungi), collected in different areas of the Campania region (South Italy). The isolates were grown on two different agar media, rich and poor for the presence/absence of dextrose and NH4NO3, and amended with 0, 100 and 500 ppm herbicide. The mycelial growth was recorded daily, and statistical analysis of fungal growth rates, determined via linear regression, allowed us to compare the hyphal extension of various macrofungi in presence of herbicide. These data represent the adaptation capacity of the fungal organisms to the peculiar environmental situation. In amended agar, all fungi exhibited a certain tolerance to pendimethalin and, normally, the fungal growth decreased with the increasing of pollutant concentration. Nevertheless, in some cases, the difference of ground reflected the different agar media. In fact, the growth of Agrocybe aegerita, in rich agar decreased with the increase of herbicide dose, while in poor agar it increased with the pollutant. Among the examined fungi, A. aegerita was the species which resulted the most tolerant to herbicide, showing growth to about 70% of the control to the highest concentrations of pollutant and for the two different agar media. Scientific relevance of the paper: No published report is available regarding pendimethalin herbicide biodegradation with basidiomycetes; therefore this work represented the first and preliminary investigation as regards. It's directed to determine the fungal tolerance to the pollutant. © 2008 Elsevier Ltd. All rights reserved.