Vicia faba seed: a bioindicator of phytotoxicity, genotoxicity, and cytotoxicity of light crude oil

Crude oil contamination is a serious threat to the environment and human health as it can contaminate food chains. Therefore, it is necessary to find efficient tests to monitor soils for crude oil contamination. The present study investigates the efficacy of Vicia faba seeds for monitoring contaminated soils with light crude oil. Vicia faba seeds were planted in 0 (control), 1, 2, and 4 percentages (weight percentage) light crude oil-contaminated soils. The seed germination and root length were measured to evaluate phytotoxicity, while the mitotic index, chromosome aberrations, and micronucleus formation in the root tip cells were examined for cytotoxicity and genotoxicity tests. The results showed that light crude oil had toxic effects on Vicia faba growth characteristics, even at 1% contamination. The phytotoxicity assay showed that crude oil reduced seed germination and root length by 45% and 61.67%, respectively. In contrast, cellular observations indicated an increase in mitotic index, chromosome aberrations, and micronucleus formation up to 3, 3.59, and 5.6 times, respectively, compared to the control. The light crude oil at 4% induced the simultaneous occurrence of nuclear bud, polyploidy, and micronucleus that may be considered as severe clastogenic and aneugenic effects. Accordingly, Vicia faba can be considered a reliable living system for monitoring light crude oil pollution in soils, even at low concentrations.