RESEARCHES CONCERNING THE DIFFERENTIATION OF THE GAMETOPHYTE OF THE FERN ATHYRIUM FILIX-FEMINA (L.) ROTH UNDER THE INFLUENCE OF A FUNGICIDE BASED ON FOSETYL-AL
The aim of this paper is to present the changes observed in gametophyte differentiation in the fern Athyrium filix-femina under the action of a fungicide containing fosetyl-aluminium. The biologic material consisted of spores collected from plants found in the Vâlsan Valley. The following experimental variants of culture media were prepared to cultivate the spores: Control (Knop solution), A1 (0.002% fungicide in Knop solution), A2 (0.002% fungicide in Knop solution), and A3 (0.2% fungicide in Knop solution). The spores were cultivated in 100 ml of solution, in culture vessels that were placed in the EKO POL KK growth chamber at 25°C during the day and 15°C during the night with a photoperiod of 16 hours of light and 8 hours of darkness. Microscopic observations on gametophyte differentiation were conducted periodically, after 9, 15, 30, 60 and 140 days from the cultivation of spores. The A1 and A2 variants showed a slower gametophyte differentiation than that in the Control variant. No spore germination or gametophyte differentiation was observed in the A3 variant. Thus, at the end of the experiment, the most affected was the A3 variant, with ungerminated spores, followed by the A2 variant, which was at the stage of elongated lamellate prothalli with short rhizoids or necrotic prothallial cells and filaments, while in the C variant, the gametophyte was at the stage of elongated prothalli with antheridia and cordiform prothalli. The least affected variant was A1, where the gametophyte exposed to the lower concentration of fungicide reached the end of the experiment at a stage close to that in the Control variant.
