The Effects of Some Pesticides on Spore Germination and Gametophyte Differentiation in Athyrium filix-femina (L.) Roth. and Polypodium vulgare L.

Abstract

The aim of this study was to assess the effects of a fungicide (copper hydroxide with 50% metallic copper) (Co) and of an insecticide (bifenthrin 100 g/l) (B) on spore germination and gametophyte development in the fern species Athyrium filix-femina (L.) Schott. and Polypodium vulgare L. The experimental variants were: V1Co: 0.1 gr fungicide/100 ml Knop solution, V2Co: 0.2 gr fungicide/100 ml Knop solution, V3Co: 3 gr fungicide/100 ml Knop solution, V1B: 0.01 ml insecticide/100 ml Knop solution, V2B: 0.02 ml insecticide/100 ml Knop solution, V3B: 0.04 ml insecticide/100 ml Knop solution and Control (C): 100 ml Knop solution. Co inhibited spore germination in all the experimental variants tested on the species Athyrium filix-femina. In the V3Co variant, after 24 days, no spore germinated. B also inhibited spore germination in all the experimental variants. In Polypodium vulgare, Co significantly inhibited spore germination. In the experimental variants containing B, only in the V3B variant the germination is significantly inhibited. Calculations showed a significant negative correlation between the germination percentage and the concentration of pesticides. The fungicide also affected gametophyte differentiation, which happened much more slowly in both species. The rhizoids of the gametophytes of Polypodium vulgare showed modifications in their differentiation and morphology that could also be related to alterations in their biochemical composition. The experimental variants with the highest concentration of insecticide resulted in the differentiation of abnormal gametophytes growing in a tridimensional cellular mass with callus morphology. The responses of plants to the induced stress produced during the testing period may be used as biomarkers of environmental pollution caused by pesticides.