The Effect of Selected Heavy Metal Ions on the Growth and Conidial Germination of the Aphid Pathogenic Fungus Pandora neoaphidis (Remaudiére et Hennebert) Humber

The effect of heavy metal ions (Cd, Cr 3+ , Cu 2 , Ni, Pb 2+ and Zn) on the growth and germination of conidia of the aphid pathogenic fungus Pandora neoaphidis was studied. The metal ions were added into the culture medium in three concentrations: A – concentration corresponding to the mean content of that metal in Polish soils, B – concentration 10-times higher and C – 100-times higher than the mean ones. The investigated heavy metal ions, except for Ni, added to the media at the concentrations corresponding to the mean content of these metals in Polish soils, did not affect the growth of aphid-pathogenic fungus Pandora neoaphidis. Ni, Cu, Zn and Cr, added to the media at a concentration 100-times higher than in Polish soils, prevented the growth of the pathogen. All the tested metal ions, except for Cu, added to the media at the mean soil concentration, did not affect conidial germination of the fungus. The conidia of P. neoaphidis were unable to germinate in the presence of the Cr, Cu, Pb and Zn ions in the medium at a concentration that was 100-times higher than the mean one. Cu and Zn caused a significant reduction of conidial germination even at a concentration that was 10-times higher than the mean content of these metals in Polish soils. This work suggest that strong pollution of soil by some heavy metals could be a restrictive factor of development and pathogenicty of entomophthoralean fungi in the environment.