Cyto(geno)toxicity of Commercial Fungicides Based on the Active Compounds Tebuconazole, Difenoconazole, Procymidone, and Iprodione in Lactuca sativa L. Meristematic Cells

The present work aimed to evaluate the effects of commercial fungicides containing the active compounds from the triazole group—tebuconazole (TBZ) and difenoconazole (DFZ)—and dicarboximide group—procymidone (PRD) and iprodione (IPD) on the mitotic cycle of the plant model Lactuca sativa L. These active compounds have been present in foods sampled at different Brazilian's states and amounted higher than recommended by law. The bioassay with L. sativa was applied to access the toxicity and better understand the mechanisms of action of these compounds in living beings. The active principles IPD and DFZ presented mitodepressive effect, statistically reducing the MI at all applied concentrations in comparison to the negative control. TBZ was the most cytotoxic active compound tested inhibited in 77% mitotic active in the lowest concentration applied. PRD alter the frequency of mitotic cells only in the concentration above that recommended by the manufacture. C-metaphase and adherent chromosomes were the most frequent cell cycle alteration observed on the treated cells, followed by bridges and lost chromosomes. Therefore, the mechanism of action was mainly aneugenic (70%). For TBZ, the frequency of condensed nucleus was very expressive (313 higher than the negative control).