The Mutagenicity of the Herbicides Glyphosate and Paraquat and Haloxyfop-p-methyl in Conidia of the Fungus Aspergillus amstelodami

The study was aimed to investigating the ability of the herbicides Glyphosate, Paraquat and Haloxyfop-p-methyl to induce point mutation in conidia of the fungus Aspergillus amstelodami. The minimal inhibitory concentrations for the herbicides were determined and three sublethal concentrations of each herbicide was tested. They were (2880, 3840, 4800 g/ml) for Glyphosate; (200, 280, 400 g/ml) for Paraquat; and (4.32, 10.8, 21.6g/ml) for Haloxyfop-p-methyl. Three protocols; pretreatment, plate incorporation and growth- mediated were used to select mutation resistant to 8-azaguanine (azgA) in the sensitive wild type strain A1. Glyphosate was negative in this respect and in all three protocol of mutagenesis. Paraquat, on the other hand, gave inconclusive results, where it was negative in the pretreatment and the growth-mediated methods, but it reduced the mutant frequency in the plate incorporation method. Haloxyfob-p-methyl, gave positive results in the growth mediated method and negative results in the other two protocols.